MJ's Japanese Multiplayer Guide

This guide includes an extensive strategy intended to help players in competitive, semi-historical multiplayer matches play Japan through 1945. It can also be deployed in single-player as well.

Conditions of this guide

In this guide I am assuming you are playing in a semi-historical serious multiplayer match with competent allies and competent enemies. In almost every competitive match there are special rules that Japan must follow (and some generic rules) and I'll be assuming these rules are in place. I am assuming this a vanilla game as well.
1. Japan must go to war with China before 1938
2. Must be a part of it's own faction (cannot join axis war against soviets until 1943)
3. Cannot go to war with the allies until October 1940
4. May only kamakazi in Pacific/Indian ocean
5. Cannot puppet China (may or may not give land to Manchukuo)
6. Must do Purge the Kodoha Faction

Introduction to Japan

Japan is an island nation that has a considerable military force stockpile at the beginning of the game. Japan is the main axis power in the Asian/Pacific theatre. Japan begins the game in a very moderate position with 19 15 (updated from not one step back) mils which can be placed on infantry equipment, artillery, and support equipment all at full efficiency. It also starts with 14 civilians as well. Japan itself consists of colonies in Taiwan, Manchuria, and several islands across the pacific along with its homeland.
Japan starts with several national spirits which do:
State Shintoism: Division Recovery Rate: +10%, Factory Bomb Vulnerability: -10%
Zaibatsus: DPP cost: +.25, Consumer Goods: +5%, Military/Civilian/Dockyard construction: +5%, Economy Law Change Cost: +25%, Trade Law Cost: +25%.
Duplicate Research Efforts: -10% research for aircraft
Militarism: +20% war support, -5% research speed, Justify time -20%, Civilian construction -10%, Conscription law cost: -25%.


These will be changed throughout the game and more will be added.

Goals of Japan

There are several goals Japan must complete to help the axis win the game. Overall Japan can practically single handedly win the game for the axis or be very inconsequential in the overall war. It's a wide range and it depends on how well you do. Here I'll discuss the main goals for Japan that can be reasonably completed in a MP match.

1. Annex China, this is not so much a goal but more of a requirement in order to even participate in WW2
2. Take over Singapore, and disrupt allied Rubber producing areas. This is the most consequential aspect Japan can undertake. Successfully taking over all rubber producing areas will mean the allies cannot produce planes and will lose the war.
3. Take out the rest of the Asian/Australian allies. Taking over RAJ, Philipines and Australia/New Zealand will be useful because it eliminates players from the game for the allies.
4. Create decisive battles against the allied navies. This is the hardest thing Japan can do because your navy and air force will always be weaker to the combined Allied navies/air forces and you have no help. It's also important because eliminating their navies will allow you to naval invade any territory and potentially delay D-day.
5. Be a nuisance the allies cannot forget. If you can successfully drag the allied attention away from Europe, even if you cannot make any territorial gains, then you have succeeded. Japan has no realistic way to defeat superior numbers assuming your opponents are competent. Typically, by the time Japan goes to war France has fallen. This means that most of the allied war effort will be directed at you which Japan alone cannot overcome. But if you can force the allies to have a considerable number of troops fighting you then that means there are less troops attacking Germany in Normandy and that is still a success.

General Staff and Doctrine

This is a WIP section, will update later.

Recommended Technology Research

Japan starts with 4 research slots and that quickly increases to 5 by the end of 1936. Typically, you have to have your own air force so there are few research slots that are going to be stuck on doctrines for a long time (no longer the case in Soviet update). In this section I will go over research priorities for Japan.

Land Research:

• Obviously you should research any infantry/support/artillery equipment bonuses or equipment as soon possible because the majority of your army will consist of infantry.
  
• If you're interested in Tanks then I recommend going down the medium tank route. To do this you should start researching light 2s before the China war (you can if your ambitious also build light tanks for the China war) and research medium 1s in early 39 and use bonuses to research medium 2s.
  
• You should have a constant research slot on superior firepower doctrine and go down the path with a right, then left if you're building tanks, if not then go Shock and Awe. The doctrines you will now use army experience for are still the same as indicated, but you no longer need to commit a research slot to them.
  
• You're free to build AA and AT if you wish but those should be situational. For example, if RAJ builds tanks then having solid AT would be good in order to pierce the RAJ's tanks.
  
• for Medium 2s, upgrade main gun, reliability, and engine to max. Also upgrade armor IF the allies send heavy tanks or otherwise pierce your tank divisions.
  
• Don't bother with Mechanized or special forces upgrades. (except marines if you use them). This decision was made considering the limited spots you had open to research (with 2/5 being spent on doctrine). With this no longer the case, you absolutely SHOULD research special warfare doctrine.

Naval Research

• You should start researching destroyers 2 pre-China so you have a decent screen ship for convoy protection.
  
• I recommend researching Carrier 3s if you can as well as super battleships because they make great additions to your naval forces. Not as viable, best to probably focus on heavy cruisers than battleships.
  
• Japan can easily research Super Battleship 2s by 1939 but you will have to hard research fighter 2s in return (again not as viable anymore). You can also research Destroyer 4s by 1940 if you focus correctly.
  
• Obviously if you can afford to spend research days on naval doctrine then Go down the right side of the base strike tree (if using carriers). If using battleships, then switch to "fleet in being" and go down the left side of that tree (I do not advise this. Battleships should be an addition to your fleet NOT your carry)
  
• The Kitakami class torpedo cruiser is not worth the focus time or production value.

Air Research

• You should research Tactical ones by the end of 1936 in order to produce for China and beyond. Once you finish the focus for the Zero I recommend taking the "Bomber Modernization" focus so you can use the 100% research bonus on or CAS 2 and finish the research in 1939.
  
• You shouldn't really have to research any other planes unless you wish to research naval bombers, the Tacs/CAS and Zeros should be enough.
  
• When you get your fifth research slot stick it to an air doctrine (I recommend Strategic Destruction). It can take up to four years to fully finish researching air doctrine and you must have one near completion if you want to compete with allied air forces. No longer the case obviously. Instead, send air volunteers to Spain to build up air experience pre-China and then use air experience earned during the China war for your doctrine of choice. For Doctrine I recommend Strategic if going for TACs or CAS + strategics, and the right doctrine if going for the standard fighters + CAS.
  
• For Zeros upgrade Engine to max, Range to max, Guns to 1, and reliability to max and make sure that BEFORE you complete the focus you have the Mitsubishi company.
  
• For tactical 2s or CAS (don't upgrade 1s) Upgrade Range to max, bombing to 2, and max reliability

I think you know how important industry/electronics are... Just make sure you have radar in Singapore... Not as relevant as it once was, Radar can honestly be ignored.


Update Note:
Realistically, Japan can now research many more things with doctrines now requiring experience instead. This is a major BOOST for Japan since Japan generates a ton of experience from the Spanish civil war and China, meaning the Americans and the rest of the allies have to catch-up to truly compete with your air or army. This may change your idea with how the China war should end (may want to grind it until 1940 for this very reason), but I still believe the industry provided by China is more valuable than the dozens of experience you may generate by prolonging it.

Recommended Construction Build

Most of the early game you're going to be constructing civilians in order to use extensively later. I recommend building Civilians until around June 1939 and then switch to mils/synthetics/fuel refineries after that point. Make sure you grab the War Industrialist PP adviser. You shouldn't build any mils before China because you should be able to kill them anyway. I also implore you to build dockyards, so you have around 30-40 of them before the war with the allies begins. They're not intended to really give you a winning chance against the allies but allow you to re-build any casualties occurred with superior tech. In terms of production it really depends. I'll show you how I start my builds in the game and before China but after that it's up to you how to produce things. Still, I implore you that for when you research an upgrade that you do not switch over ALL of your factories to it but instead switch over a few to the new line. Before the war starts you should have about (rough estimates):
105 civs, 10 Synthetic Refineries, 95 mils, 35 dockyards.

That pretty much covers that for construction and productions for the game. Remember this all depends on strategies but this should give you a rough idea for what a Japan should do.

Pre-China Focusus/PP purchases

There are ten focuses that are optimal to complete so you may go to war with China right around the end of 1937. There are also a few political advisors and decisions you want to undertake before China rolls around the corner.
1. we start with "Purge the Kodoha Faction", grants +10% stability

2. Upon completion of that focus start "Guide the Zaibatsus" which will buff your industry and add 2 civs.
STOP: You're going to want to wait a few days before picking the next focus so you reach 150 PP at which then you can purchase the silent workhorse.
3. After waiting now you may select: "National Mobilization Law" which changes your economy to war economy.
4. Select "National Research Policy" to receive and extra research spot.
STOP: You're now going to wait to select "Nationalize War Industry" until you change your trade law to Free trade (so you can trade with the axis 1 for 1).
5. Select "Nationalize War Industry" which gives 2 mils and 2 civs.
6. Select "National Defense State": changes your economy to total mob. Around this point you'll want to choose the decision "Prioritize Steel for Guns" which gives you +4 mils putting you at 26.
7. "Spiritual Mobilization" counteracts total mob conscription debuff. Also, you'll once again reach 150 pp and I recommend grabbing the military theorist for -10% research time on all land doctrines.

In terms of PP, from now on out it's your decision. But for the next few I recommend advisors that'll enhance your ability to fight China.
8. Liason Conference, you must now start heading on a path to war with China.
9. Greater-East Asian Co-prosperity Sphere: makes your faction.
10. Marco Polo Bridge Incident, prompts the China war decisions.

This is the optimized way of preparing for China. This way will grant you additional PP, mils, civs and resources for the fight against them. Now I'll move on to my strategy for fighting the Chinese.

Unbeatable Strategy Against China

Ok I'll admit it... It is beatable... if you forget to put artillery in your divisions... The reality is that China is NOT supposed to be able to defeat Japan in a war, short or prolonged. China's greatest weapon is time. If China can survive into late 1939 then Japan has failed and will be severely behind schedule. You'll want to have China defeated no later than June 1939, doing so would mean you're perfectly on schedule to commence whatever allied war meta you've decided on. This strategy in my case has not been beaten by any China, and it's really not that complicated.

What I do:
I build 17-2s, 17 infantry and 2 artillery and Tactical Bombers. I decided on this back during the Asian DLC in March 2018 because they nurfed soft attack for Infantry. This IMO is better blend 14-4s because it provides greater defense so China cannot go on any offensive against you. It also provides a very equivalent amount of soft attack that a 14-4 does and is overall cheaper. If you follow my steps below you should be able to pump out approximately 50 of these divisions before war begins.


Here's what you'll need:

• About 10 mils on Infantry equipment which should rise to 12 when you get the mils.
  
• 1 mil on motorized
  
• 3 mils on support, to 4
  
• 5 mils on artillery
  
• lastly you'll want 5 mils on tacs when they become available (you should lease tac1s from Germany if necessary and avoid a penalty when switching to your tac1s).

The reasoning for all of this is in order to fully supply your divisions pre-war you need much more Infantry Equipment than artillery, so it takes priority. Also, Japan starts with very little support equipment so you have to spend more than a normal amount of mils making them. The 1 motorized is in case you run out when implementing a motorized support company (I like to add signals to my troops).

Also to prepare for the war I recommend building a lvl 10 port in Dalian as well as building a lvl 3 airport in East Hebei before the war begins. This will help with supply and the air war in Northern China.

Now for the fun part. KILLING CHINA!

The Beginning
MAKE SURE YOU HAVE ENOUGH PP TO ESCALATE WAR
You should have enough divisions to field 2 full armies of 17-2s and a few extra on the side. With one of those armies you will push down from Beijing to the center of the country (duh). With 10 of those divisions from the second army you will naval invade these sections of Nanjing.

These should be successful because it's very difficult for China to defeat your naval invasions when you have air superiority, shore bombardment and strong troops that have high org. But even if they're not as successful as you'd like; by simply attacking the capital region of China you destroy their supply around the country (also stick your commando general on these troops). It's basically abusing the supply system of Hoi4 because by attacking the heart of the supply and ruining all the infrastructure there you cause the rest of China's army to attrition and will make them easy to kill as you march down from Beijing.
Once these invasions are complete be sure to schedule more especially on the Shandong peninsula in order to threaten a complete cutoff of the Beijing front.

Yellow River Line
At this point you've hopefully taken part of the Nanjing capital, and part of the Shandong peninsula as well push down to the Yellow River Line that all China's fall back to. The weakest part is typically near the shore as you can throw more resources at that part. The main objective the line holds is the airfield just south of Jinan which will effectively eliminate any Chinese air presence in Northern China. Take that airfield and move as many planes there as possible. It should be noted that supply actually becomes EASIER the farther you move into China (the opposite of the real war). This is due to the supply states being divided in a way that makes it advantageous for you to push even further.

In the picture you can see that I'm about to enter another supply state. When I enter that state my troops will attrition less. You can also see that I encircled some troops and took out the coastal part of the yellow river. Keep in mind you can use maintenance/logistics companies and advisors to counteract the effects of attrition.

Finishing Off China
Once you've taken the capital, pushed through the entire Yellow River and are advancing on PRC territory and mainland China it's pretty smooth sailing. You can't relax of course but you should pick fights you are green in only and continue to mow down the Chinese as you make your way to Chongqing for capitulation. In reality, it's basically a massive push towards the center of China at this point. Finish the job.

The Aftermath
Once you have defeated China you should either annex it or give the cores to Manchukuo. If you annex it you should have around 60 mils and 85-95 Civs (depends on how China builds). As well as this you inherit all of the damaged infrastructure and resources from China. Giving it to Manchukuo though actually gives you ~50 mils and you'll have ~60 civs but Manchukuo will have ~12 mils and ~45 civs. You should only do this if Manchukuo is a player you can trust and if the rules allow it. Not to mention but you can actually have more resources due to the fact that Manchukuo must give you their resources for dirt cheap.
At this point you must prepare for war against the allies.

Post/current China Focuses

This section will include a recommended path for focuses to choose immediately after the Marco-Polo incident focus is completed.

Typically after China you rush the "zero" focus to instantly unlock carrier fighter 2s to build as your main fighter force. You build these as your main fighters because of the free research, decisions that reduce their IC cost, multipurpose, and less resources used. They are a tad bit slower and have less range than fighter 2s, but their benefits outweigh the negatives.

First focus: After finishing the Marco-Polo Bridge incident you want to choose New Naval Estimates which adds 4 dockyards and a 100% research bonus towards super heavy battleships.
2: Carrier Warfare Experiments, 2 100% research bonuses towards naval doctrine.
3: First Air Fleet, +20% sortie efficiency from aircraft carriers.
4: Fighter Modernization, 100% bonus for heavy fighters and normal fighters
5: Agility Focus, allows you to choose the Mitsubishi company as air designer (+20% agility and +10% speed to fighters and carrier fighters).
STOP: You MUST pick the Mitsubishi company as your air designer BEFORE finishing the next focus.
6: The Zero, unlocks the Zero (unique carrier fighter 2). If you have the Mitsubishi air designer chosen before you finish this focus the zero comes with the added benefits.

Now you have unlocked the zero and should immidiately begin producing them. They are extremely important to your war effort and you should upgrade them first from any air experience you picked up from China.

After finishing "The Zero" I recommend going down "Bomber Modernization" to recieve a 100% bonus towards researching Tactical bombers. Use that bonus to quickly research Tac 2s.


At this point your next few focuses will depend on the build you are pursuing for the allied war. In my next sections I will go over some build strategies for the allied war.

Land Focused Japan

This section, is not meant to be replicated exactly. It is intended to provide knowledge that can assist you build in this particular fashion and find the best fit for you.

Focus Path
Assuming you have followed the previous track correctly you should follow this path if you wish to focus on a land based army.
1. Army Expansion Law: 30 Army XP
2. Army Expansion: Grants a training time advisor
3. Supremacy of Will: +10% division attack, division defense and recovery rate.
4. Sign Tripartite Act: Guarantees all around!
5. Strike South Doctrine: 2x 100% naval doctrine bonus and unlocks "Demand Indochina"|
6. Develop Chinese Resources: +20 aluminum and more decisions to improve resources.
7. Coal Liquification: 100% synthetic bonus & 1 synthetic refinery.
8. Warrior Spirit: allows kamikaze's.
At this point take what you need the most, or do a continuous focus. And remember that you shouldn't necessarily follow this exact order if you find something else is more important.

Industry
You should build civs up to May 1939. This will give you a large amount to trade and continue to build once war starts and to prepare your military factory count. Once you finish with civs you should build plenty of mils and some dockyards for screen/convoys. Don't forget refineries and fuel silos to store up plenty of fuel. Numbers for 1941 should be around:
90-100 mils,
25-30 dockyards,
85-100 civs,
10 refineries,
14 fuel silos
Don't follow this religiously. It's only supposed to give you a general sense of what you be at.

Production
As a land focused Japan you will have the capacity to build up a ton of divisions including tanks. For infantry lines you'll need, motorized, support equipment, infantry equipment, artillery and anti-air. For the tank line you'll produce Mediums and medium SPAA. Planes will be pretty standard with mils on zeros, and tactical bombers.

You'll want anti-air because a support company of anti-air severly reduces the effectiveness of CAS for the enemy.

Mediums are necessary because they're fast, tough and powerful. SPAA is also good for 11-2-8s as they provide significant air attack to your tanks.

I recommend dividing your mils in the following order:
20-25% on guns, 10-15% on artillery, 5% on motorized, <5% on AA, 10% on support equipment, 20-25% on Zeros, 10-15% on tactical bombers, 1 mil on SPAA and the rest on mediums.

Upgrades for Tanks
I'll just cover SPAA, SPG and normal mediums for upgrades.
Normal Mediums: Max Main Gun, Engine, Reliability and armor. Upgrade armor and reliability sooner if you feel like the allies will pierce your tanks or if your tanks reliability goes below 60%.
M-SPAA: Anti-air gun, Engine, reliability.
M-SPG: Artillery Gun, Engine, reliability.

Naval Focused Japan

This section, like the last, is not meant to be replicated exactly. It is intended to provide knowledge that can assist you build in this particular fashion and find the best fit for you.



Focus Path:
1: Assuming you have finished the focus path described under Post/Current China focus path you should start with "Modern Escorts" which provides a +100% research bonus towards destroyers. I recommend you use this bonus for destroyer 3s to counter Allied submarine 3s and provide better convoy protection.
2: After that you should go down "Cruiser Modernization" which provides a 300% research bonus toward heavy/light cruisers. I recommend using this bonus for Heavy Cruiser 3s or 4s if your ambitious.
3: Long Lance Torpedos which gives +20% torpedo screen penetration. Basically means there is a 20% higher chance your torpedos hit a capital ship or convoy when they're protected by destroyers/light cruisers.
4: Expand the SNLF, +100% bonus towards marines and +2% special forces modifier. Useful to have more marines on the field for naval invasions.

After this we've completed the naval section of the focus tree and move on to other sections.
5: Sign Tripartite Pact, gurantees' all around!
6: Strike South Doctrine, unlocks Indo-China decision and 2 100% naval doctrine bonuses.
7: Warrior Spirit, allows Kamikaze's.
8: Army Expansion Law, +30 army XP.
9: Army Expansion, unlocks trainer advisor.
10: Supremacy Of The Will, +10% divison attack, defense and recovery rate.

After finishing everything you should focus on either ship building or aircraft production (depends on what you need more). You can also consider skipping a few focuses in order to switch to a contineous focus sooner.


Industry:
Rather than build civs until mid-1939 you should stop in early 1939 and focus on naval dockyards, refineries and fuel silos from here on out. A Navy focused Japan will build a very little amount of mils, if any. The reason for stopping to build civs earlier is because naval strategy coincides with build strategy, IE, ships take a long time to make. Therefore you need many more early dockyards than mils in order to perform a well executed naval Japan. You'll also need more synthetic refineries than usual due to fuel costs of Navies being much higher than land units. Here are numbers you should be looking at by 1941:
90-100 Civilian Factories
60-70 Naval Dockyards
60-70 Military Factories
10-15 Refineries
~10 Fuel Silos
Don't follow this religiously. Build what suits your needs.


Production:
I recommend building 4 different ship types as Japan.
Carriers, Heavy Cruisers, Destroyers, and Submarines.
I'll go over why for each one.

Carriers: Best ship in the game, and works well with Japan's sortie efficiency bonus, focus on carrier fighters and naval doctrines. You can build the Akagi class carrier 1 ships because they are cheaper and have higher deck space than carrier 2s but they also have a shorter range and are weaker.

Heavy Cruisers: It's pretty simple math, Heavy cruisers are signifigantly cheaper than battleships with equivalent stats. Since you won't recieve any bonuses for battleships you can only build battleship 2s realistically. Battleship 2s are 2.5 times more expensive than HC 2s and 2.16 times more expensive than HC 3s. If you compare their stats over their costs, Heavy Cruisers are a way more efficient ship.

Destroyers: Basic screen ship; every navy needs them. They provide solid sub detection and death charge attacks to protect convoys and capital ships from enemy subs.

Submarines: Basic convoy raiding ship. They have long ranges and can be used to squeeze the enemy out of islands or trade.

For production I recommend putting 25-30% of your docks on carriers, 15% on destroyers, 15-20% on convoys, 20-25% on Heavy Cruisers, and 15% on subs. I did those estimates off having around 70 dockyards and how I'd personally split them.

Upgrades:
Carriers: deck space, deck space, deck space....
Heavy Cruisers: (in order) Max gun, Engine, reliablity.
Destroyers: Max AA and ASW.
Submarines: Max torpedos.

Strategies on how to defeat British Raj

The time is upon us... It is time to enter the war against the Allies... Now these are situational conflicts because you'll see a different number of strategies. I am going to focus on each allied nation in the Asian theatre so you have a comprehensive way to defeating them. First is RAJ.

The RAJ can go a number of different routes from AT, 14-4s, cancer 10 width or 20 width etc. But they generally follow a few rules regarding their defense. TLDR: You need air superiority to win.

The Mountain line: Almost all Rajs like to hold this line

This is a good line for Raj since it's mostly behind a river and all tiles are either rainforest, hills or mountains for Japan to attack through. The only way to break through this line is by having air superiority. Generally if you control all the territory up to this line then you can build an airport in Mandalay and Burma which can provide you the capacity to force air superiority in the region. Of course this depends on how many planes the allies also put up HOWEVER generally speaking the allied plane manager will be busy swapping the planes from focusing on Singapore to Burma and if you can catch them off guard you may be able to push a little farther. The line also has problems because it has spots that are not well suited for defense. Take this little spot here for example:

It is grassland and on each side is surrounded by mountains, a river and forest behind it. It's suitable to be used as a point of breakthrough. Another tactic is to naval invade behind Raj. If you can take the city of Dacca and it's port then you can essentially cutoff RAJ's line from the rest of his country which would be a killing blow. Easier said than done of course as naval invasions are rather difficult to pull off. First you need naval superiority, then you need a sufficient amount of troops to invade and then the element of surprise in order to cut off his army.
Unless Rajs divisions are so insufficient, or the player is terrible breaking through this line should be difficult. However once you break through, the RAJ player is in a bit of a scramble to get his troops organized before you close the southern half of the line. Once that happens they typically fall back to the Dacca line:

Here you should build airfields in Assam which can be used to breakthrough the line. RADAR is also very useful in Assam which will help with your air superiority. Due remember that strategic bombing can actually bust their own airports leading them unable to fly as many wings and therefore giving you a greater advantage. After this point the RAJ's army will probably be to weak to continue fighting in a manner that is sufficient to repel your invasion. There are no set lines after Dacca for the RAJ to fight as there is simply to much open terrain in the rest of the country. Most RAJs quit if you surround or otherwise decimate his army after Dacca.

To summarize: Air superiority and finding weaknesses where they exist. If he has left a port open or inadequately defended, attack it, if a spot on the line is weak, exploit it. I like using tanks against Raj in some of grassland sections of the line because most RAJs don't build AT or tanks themselves and don't have the necessary Hard Attack to repel tanks.

Strategies to defeat the Australians/New Zealand

Invading Australia
Killing Australia/New Zealand can either be a first priority, or a final priority in the war. This depends on whether or not the Australian player is defending his territory well enough to repel a naval invasion. A bad Australia will neglect his homeland and you may be able to exploit this if you can achieve naval superiority in a few regions for a short while. This means you can potentially invade Australia on the outset of the war if the Allies are not fully prepared. I recommend using cavalry as auxiliaries in order to encircle and take out any Australian forces inside of Australia. If Australia falls, New Zealand falls as well.
Most Australias' send their best troops to Singapore for defense. Obviously taking out Singapore means Australia has lost a significant chunk of their army and should be easy picking for you to destroy. This is due to the manpower issues and production capacity Australia has. It's rather low and you should be able to exploit them.
Dealing With Naval forces or planes
Some allies will have their Aussies and New Zealand players build up navy or air forces as a priority to help fight you. Typically New Zealand can build Submarine 4s by 1941 and have a quite a few wolf packs. To counter you must build screens and I recommend using focuses to research Destroyer 3s as quickly as possible while also putting around 10 dockyards on Destroyer 2s and 3s when they become available. Some Australians also like to build Naval 2 bombers in addition to their core army. The only way to counter these is by putting AA on your screens and make sure you have your fighter wings in sea zones on interception.
Defending Islands
You should have garrison on most islands you control. You can neglect the Caroline and Marshall Islands but they can be useful if you plan on naval invading Australia in mass. Otherwise you should have a significant force on the Islands of Palau, Saipan, Iwo Jima and Marcus Island. Those are important for defense agaisnt allied attacks on mainland Japan.


That covers Australia and New Zealand. Once again this is situational. If they are weak then taking them out quickly is a viable option (especially if you can't push in Singapore). If they are strong then avoiding them while taking other objectives is your best bet.

Strategies to take over Singapore/Dutch East Indies

This is the pinnacle goal for Japan. Taking Singapore and the Dutch East Indies is extremely important and can decide the entire game if you're successful. Here I'll list methods of taking these areas.
Naval Invasions
Obviously you need to naval invade several areas in Indonesia, and British Malaya to fully take over the territory there. This all depends on how successful your invasion from northern Singapore is. If you are stuck in the north then naval invading Borneo, northern Sumatra, and Andaman is a good way to draw attention away from Singapore and allow you capture additional airfields in order to gain air superiority. In fact taking over Andaman is probably the most important early naval invasion you can accomplish as that will allow you to put up more planes in Singapore and Burma when you need to. Invading Borneo is generally easier than invading Sumatra because it is of less importance to the allies and they only have a limited number of troops they can use to defend ports and airports in the pacific.

The Air War Over Singapore
Taking over Singapore will require air superiority. To win air superiority you must have solid doctrines, solid planes, and a lot of air force capacity in the region. Generally speaking the allies can put more planes against you in the region and you shouldn't fight them if they severely outnumber you in terms of air power. Instead what you should do is flip flop between sending your air to Burma and Singapore, keeping the allied air controller on his toes (remember he still has to micro Egypt and Europe at the same time as fighting you). You should also research radar, or have Siam do it. lvl 3 Radar should be good enough to cover the entire air region. Lastly is the use of tactical bombers. Use tacs to destroy the airfields in surrounding areas like Andaman (which is in a different air zone) and use them as close air support when you begin pushing into Singapore.
The Supply War
Supply is a problem for Japan in the region. Since you'll need access to a lot of supply in the region you must decide on how to supply your troops. One method is by building several ports in the state of Siam which is probably the easiest way to supply troops. Another method is by building infrastructure across China and down to Singapore to supply your troops. This is more costly than the other method but it's safer since you're convoys won't have to travel as far.

The Land Invasion
Again the invasion of Singapore is dependent on all of the factors above but it's also important to understand objectives and concepts when taking Singapore. The most important objective when taking Singapore is the airfield, it's also where the radar tower goes. Taking that tile will mean you have defeated the allies in Singapore. I've discussed how the allies defend Singapore in my previous Australian guide and you can see the lines there.

MJ's Australian multiplayer guide 

A Guide for Hearts of Iron IV

By: mjb2k

This guide should help new Australian players grow into the shoes of an important Asian ally for the allies. This guide is intended to be used in a try hard scenario with adequite rules, competant allies and competant...

If you have tanks and air superiority, then you should push in the center of the region. Because air superiority gives the enemy a movement debuff (among other things) it can allow you to encircle allied troops in the peninsula. The reason it's so hard to push is due to the terrain (all hills, mountains and jungle) and the level of which the allies try to defend Singapore. It doesn't take much of an error by the allies for you to surround their forward line since the distances are so short. Do this and you'll have an easy road down to Singapore. You can also attempt to naval invade the airport (simply taking it is enough to decide the fate of Singapore) or paradrop behind the lines to cut them off (assuming they have no troops there to keep fighting). This should only be done if the allies are completely unprepared for war.

That covers Singapore strategies. TLDR: Naval invade other areas first if you're in a stalemate, switch air war from Burma to Singapore depending on where the allied planes are, and make sure your supply lines are well protected.

The Manchukuo question

The Manchukuo question is in regards what to do with Manchukuo. This really depends if they're a player or not. If not, then feel free to do whatever you want with them. Ignore them, annex them, invest in them, it doesn't really matter because you'll reap any benefits you get out of Manchukuo.
But if Manchukuo is a player under your control then there exist strategies that best benefit you and Manchukuo. I will go over a few here and I discussed ways Manchukuo can implement them in my old Manchukuo MP guide.

MJ's Manchukuo multiplayer guide (UPDATED FOR 1.5) 

A Guide for Hearts of Iron IV

By: mjb2k

New to MP? Want to try out Manchukuo with it's newly updated focus tree in Waking the Tiger? Well this guide is for you! Here I will discuss a variety of strategies and ways that Manchukuo can become a considerable...

Typically, Manchukuo is best if you force them to specialize in a certain field, like tanks or planes. I will go over some of these strategies, but it must be understood that in order to have a realistically capable Manchukuo you must gift them a large swath of China if allowed under the rules. Giving them a lot of the aluminum/steel resources allows you to buy those resources for a much cheaper rate than if you owned them yourself. Manchukuo also should have cores on all of China when you defeat them so you lose 0 factories when Manchukuo takes all of their land.
It should be understood that in certain rule sets you cannot do this so the point is mute. All Manchukuos should however do the following things:
1. Build 10-20 widths (whichever is allowed) for the line against China and occupying China, this will not be their fight.
2. Build infrastructure and Synthetics. Building infrastructure and synthetics in Manchukuo is very beneficial to Japan economically since you can practically take all of their resources for free (remember Manchukuo should always be on free trade).

The Tank Strategy: One of my favorite things to do with a Manchukuo player is to have them research significantly into the Mobile Warfare Doctrine tree and have them build a considerable number of medium tanks to be used in breakthroughs in Raj or Singapore. These tanks can be much more effective than Japanese owned tanks can due to the doctrines used by each side. Superior Firepower (the best doctrine for Japan) has weak bonuses for tanks but Mobile has incredible bonuses for tanks that make them much better. The strategy is also straightforward. Have Manchukuo research into Medium tanks and have them build as many as possible while also having one mil on motorized and infantry equipment. You can lease their mediums for FREE and research them and build some of your own to lend lease to them. You should also cover all of their support equipment costs and any infantry equipment costs as well since you'll be mass producing those weapons.


The Plane Strategy: The next strategy consists of having Manchukuo be the plane controller for you. I haven't played this way in a while, but I believe it's still doable. Essentially, you have Manchukuo build planes exclusively and have them research an entire air doctrine while you lend lease planes as well (except carrier fighters). Basically... Manchukuo becomes the plane ♥♥♥♥♥ for Japan. It allows Japan to not have to invest in researching any air doctrines and certain planes. It's also economical because Manchukuo has a mainland connection to Europe which means they can buy aluminum without the need of convoys.


Those are all the strategies I'm going to cover for Manchukuo. Manchukuo is just a minor, an unimportant one at that too.


Update Note:
Manchukuo has appeared to garner more relevance in multiplayer, mostly driven by the fact that they are allowed to control China. There are now other strategies you can do with them, mainly potentially having them build marines and amphibious assault vehicles. That breakthrough could come in handy when combined with legitimate marines.

How to operate your Navy

This section is dedicated because I think a lot of people (including myself) are really puzzled with the new naval warfare changes. So I'll just go over a few things to do to prepare your navy for war against the allies.

Organizing your Navy
First off lump all of your ships into one giant fleet.
Now separate all of your submarines from the fleet and make two theatres.

Starting with subs, divide them into little fleets of 3-6. Now stick each of these fleets with these admirals (I recommend them because one has a wolf pack bonus and the other has a spotting bonus).

Now for the surface fleet: Take half of your destroyers and separate them from the main fleet.
Separate them into 8 destroyers a fleet.
Now take all of your light cruisers and separate them into groups of 3.
The rest of the fleet you should stack into one fleet.

This is a rough idea. I did this in single player and since there is no 1:1 trade I didn't build naval ships for a long time so you should have more than this amount of ships in a normal MP game.

My General Strategy for Navy
The submarines will exist in their packs and should be sent to regions where enemy convoys travel. That is their primary function so make good use of them. Here's where I like to put them typically:

These regions are selected because they typically don't have as many screen ships and US/New Zealand/Australian convoys like to travel through here.

The destroyer's group primary function is convoy defense. I like to put them in these regions:

These are where most of your convoys travel to so defending them is vital for supply in these regions.

Our light cruisers will be patrol ships and set on do not engage in the same regions as our destroyers are. They are intended to keep submarines away and not really to fight them.

Finally the main fleet should be used as the primary force and only sent into the open IF you have air supremacy in a region. Without air superiority you have no hope of defeating the allied navies. Also make sure you use kamikazes in regions where the allies leave their ships. When doing so set your air wings to low intensity so you don't have all of your planes commit suicide at once. Keep in mind you can also use shore bombardment for naval invasions. For full effective shore bombardment put 2 battleships next to a tile you're invading.

Do make sure that you have your assembly lines assigned to fleets so you don't have to constantly micro manage every new ship that is built. That sums up what you need to know for the naval war.

Intelligence

To me intelligence doesn't add that much to the game, it really only moved some things for which there existed buttons for to instead now their exists "operations". But that being said intelligence can provide some unique benefits if done right. Here's what I recommend building/doing with intelligence and spies.

Play more defensively than offensively:

• Counter intel with spies more so than using them offensively to steal blueprints.
  
• Focus on upgrades that boost defense over effectiveness against the enemy.
  
• Examples: Passive Defense (MAX IT), Interrogation Techniques, Suicide Pills

Decryption is pretty good:

• Gives you a solid 30-day bonus against the allies. I recommend deploying it on someone like Raj who can't research encryption so it's much easier to crack their codes.
  
• Also makes it harder for the enemy to use this tactic against you.

Become the Spy Master:
I myself overlook this often, but it's definitely worth it as it allows you to recruit more spies from different backgrounds.

Conclusion

Japan is a nation that is on the ropes all the time. Adding up all of the allied nations in the pacific they nearly match your military and civilian counts, then sprinkle in some American/British forces and you quickly find yourself out numbered and out gunned. But with this guide should make you competitive and force the allies to focus attention on you helping the Axis. Remember it's not always about the flashy wins where you take Singapore or RAJ in a few months, but the long war and how you impacted allied plans. Forcing them to send thousands of planes to Asia and dozens of divisions means Germany has breathing room to invade the Soviet Union which ultimately decides the game. By maintaining your competitive edge the allies will have to divert attention to Europe allowing you the opportunity to accomplish your goals. I hope this guide helps you in your games. Now go out there and kick ass!

No More Updates

I've moved on from HOI4 and will be unable to update this guide with more content. Anyone has permission to use the work in a new guide so long as they credit this.

[Dragonofhonor]

Thanks for updating the guide with the newer DLC. I always come back to this since I want to try to have a successful Japan run in single player.

[sirdalton2]

Thx for the Guide

[hophop]

Awesome Guide- I was a shitty ass Japan even in singleplayer back then- Good guide that tells you what you did wrong and what to improve- people who's leaving negative comments should actually appreciate him actually spending time writing this for beginners. Took out East Asia in 1942 by following this guide. Cheers.

[Germanfan]

Bruh I come out of quarantine and after wanting to play Kaiserreich japan in single-player I come across this tutorial. Honestly I can't think of anything better, I have seen lots of bad tutorials(THOMAS) and I couldn't really handle the beta-maleness of mp lobbies(although other more private games are sure to do better). This guide doesn't tell you what to do or try to make u the best player in the world but just tries to make you understand WHY your losing. Because honestly if your losing against everyone in hoi4 thats fine as long as you can improve and change your play style. Its also kinda disappointing how a guide made a year and a half ago feels like it was made yesterday hoi4 tf u doin?

[KarlD18]

Very nice guide. Worked well for me every time. I don‘t get what problem the two guys underneath me have with the guide. I hope they can enlighten me, instead of just saying bad guide and done. Furthermore is the guide attached to one of the replies kinda weird.

[Joesmoe]

bad guide. doesnt know navy and says to give cores to manchu WHAT

[Δ= b2-4ac]

Very good guide.
What I do criticize is never ever go Tonk Japan it's just not a smart decision becuase will they work in Indian mountains or EI jungles?
and you dont have the Industry to support them I mean you need to mass produce carrier fighter 2's and so on, so really you dont have the industry to support it especially when you go navy Japan.
Land Focused Japan is really the only option you have I mean your job is to distract the Allies long enough so Gormany can kill Soviets, so breaking Malay and Raj will not only take all the resources but this will also create pressure for the Allies, so you really need a strong Land and Air army to break the Allied defences.
Naval Focused Japan has a lot of different opinions on how it should operate so I cant really give an exact strategy for them but just remember that you have Kamikaze which can destroy a US fleet and also remember that sometimes the US will go trade interdiction 300 cruisersub2 -10%visibility and fuck you up

[aaa]

Japan ends up getting raped in vanilla against good allies. You end up like this when you decide to ignore navy. Imo, japan should go 160docks trade interdiction(it is the best naval doctrine even for surface ships) and you build up a fleet, cruisers with armor1 should br enough to survive the bullshit of burke dd3 spam usa, but however, you won't be able to kill raj mostly likely so you ignore him. The rubber islands should not be an issue since your fleet wins the rubber islands and singapore will be kept as "hostages". Since you can't kill raj you cap ast and nzl then go for south africa and start island hopping into the atlantic until you cap ireland, then it is your decision sealion or highcastle.

[mjb2k]

@Dragon Yes true. Destroyers and Subs for Japan are one of the last things you upgrade so I put the AA there in case the player had extra naval experience to spend. It's not meant to be important.

[mjb2k]

@Dragon Of course Japan can go full navy but that typically means you can't build tanks. Building Navy can be really strong of course especially if you have a good understanding of naval combat in hoi. I have a general understanding to make a strong navy and win battles but I am no expert which is why my naval section is fairly basic. You typically can't build tanks if you build Navy because of the amount of resources needed for navy (which coincides with tank production) and the construction time you'll have to spend building dockyards rather than military factories and research time necessary for naval doctrines. Navy also needs to be started early because ships take so long to construct. Again this is meant to guide Japan players not down any particular path, but to help them understand different strategies and decide what's best for them. I'll add some more information for post-China and I'll include a navy focused build.