How to get the True ending (World of Ashes)

Hello, everyone! In this guide I'll try to explain how to get the true ending in CINERIS SOMNIA.

Introduction

CINERIS SOMNIA has true ending, which you can get if you found four chunks of ash (parts of the Ash Key): each one in every chapter. Chunks of ash are easily missable (and if you missed one of them and finished chapter you can't get it after), so in this guide I tell you where and when exactly to find them and what to do (if needed).

Charlotte's Chapter

When Charlotte tell you about Sweet Medicine talk to her few times. She must tell you about her father and his work.
After you gave her Sweet Medicine and receive Letter to Father go to room 216. Go inside (door will be closed if you didn't talk with Charlotte earlier like I said) and get the chunk of ash from the sewing machine:

Marie's Chapter

After events in Dollhouse (where you saw Marie's memory about a secret of the blue bird) go to the pond/river where you earlier pick up the birdcage for Marie. Examine the wooden toy boat and get the chunk of ash:

Ophelia's Chapter

In the end of chapter when you get all tools needed to open (but not open yet) the coffin in Ophelia's bedroom and saw all past memories (by peeking to all doors) go to Library on the second floor. Get the chunk of ash from hat and umbrella beside lamp post:

Last Chapter

On the top of lighthouse examine the desk:

Notes

I could miss something or make a mistake so any recommendations and corrections are welcome.
Thanks to BOWSETTE and Dinnyforst for some tips on the search of chunks of ash.

[The end of eternity]

This is a thoughtful game, with the explore of human's inner world. Also, I thought the empty book at the end was to stick to the topic. Everything already became ash and noting could be changed in the real world. As a designer, I appreciate this wonderful art work.

[Kirito]

Yeah I thought about it for a long time the doll and the fish might be puns but still creepy.

[Krusnik777]

I don't think that the big head and the big fish are easter eggs. Just atmospheric grotesque (in a good way).
Glowing white letters are, in my understanding, messages from someone (not devs) who talk with the Tall Man through them. They can be found in every chapter.

[Kirito]

Nice guide, also did you notice the easter eggs? the big head of the one eyed doll, the big fish and the devs letter? I saw it in marie's chapter down the bridge where you get the axe near it is a column of the bridge a glowing white letter of devs i think it was like this (arent you forgetting something) also the last letter was in the light house after you got the last chunk of ash read the book.

[ガメ]

Nice!

[Dinnyforst]

Thanks for making this guide too. Well explained!

[DX5536]

Thank you for this mini guide!