Coco

[Ryouko]

Im sad Coco isnt a playable character in the game. Sana is an Alumni too and playable. Best Dragon

[ChocoParfait]

It is up til Gamers and 3rd gen not even out yet,
We literally have the plug type Asacoco in game, you just need more of that.
no need to rush it.

[Devoted to Suisei]

GEN 3, GEN 4, GEN 5, Holo X and GEN 3 (EN) are not out yet, just wait some time for the uptades

[hopefuldeath]

You're sad Coco isn't playable but you apparently don't give enough a crap about her to even know what generation she's part of, apparently.

[Dedlok]

I will add that Sana was in the game when it first came out on Itch.io and at the time she was still active. She graduated sometime after.

But I am sure Coco will be playable when Kay and company get around to adding JP Gen 3. Especially since she has so much representation via various items. Not to mention Coco is in Idol Showdown.

[DarkMatter]

I can't really say much about graduates, but Kay Yu himself said they'll eventually add everyone, HoloStars included. Subjectively I'm pretty sure all former HoloLive Members will join in time. I mean, even Aloe got a reference with the headphones and she was with HoloLive for just two weeks.

[Peshmerga]

There's a certain green hair necromancer in Gen 3. Don't know if Kay Yu will include or not. Since Rushia has been terminated by Cover.

Coco from gen 4, her archives will always be up.

[Shirojacky]

Rushia's oshi mark (alongside everyone else's who sang 今宵はHalloween Night!, i.e. Choco, Mel, and Shion) is in the game, so I doubt Kay Yu would exclude her as a character.

[The Wise Wolf]

Kay Yu did answer "yes" to the question "Is there a chance to see Friend-C and Friend-R later on?" at some point, so there is that.

[Blazikenowen]

honestly I am surprised coco pekora etc weren't added earlier then the newer holotubers as nice as it is having newer from the start I feel the older gens woulda been better being first

[The Wise Wolf]

Originally posted by Blazikenowen:

honestly I am surprised coco pekora etc weren't added earlier then the newer holotubers as nice as it is having newer from the start I feel the older gens woulda been better being first

Kay Yu is adding characters in Gen order, he said he considers that "most fair".
I don't recall if he said why he started with EN, but he did say he did ID out of order since otherwise they would have to wait a long time and since it's a small branch they fit a size of an update perfectly. Originally he planned to add a gen of JP and a gen of ID (iirc), but decided that a dedicated update for ID makes more sense.
We can expect JP Gen 3 and 4 in the next update (unless he decides to add a gen of stars or something first).