A doujinshi is a self-published work by an amateur author. When it relates to an existing IP, it is a derivative work that is usually tolerated by the industry and IP/copyright holders. Many authors started out as doujinshi authors. I’m pretty sure Namori herself started out that way. https://en.wikipedia.org/wiki/Doujinshi This would mean that usually an “official doujinshi” is not really a thing that makes sense. Confusingly, an official doujinshi seems to exist: https://mangadex.org/title/fdbf786d-6075-45d5-b211-2a58786392f9/yuri-yuri . Some of the volumes are done by Namori herself and others are done by other artists (how it usually goes).
Kyoko probably talked them all into it to promote her doujinshi.
Is this an in-universe reference, or a real thing that happened?
Like, is there official doujinshi for YuruYuri?
A doujinshi is a self-published work by an amateur author. When it relates to an existing IP, it is a derivative work that is usually tolerated by the industry and IP/copyright holders. Many authors started out as doujinshi authors. I’m pretty sure Namori herself started out that way. https://en.wikipedia.org/wiki/Doujinshi This would mean that usually an “official doujinshi” is not really a thing that makes sense. Confusingly, an official doujinshi seems to exist: https://mangadex.org/title/fdbf786d-6075-45d5-b211-2a58786392f9/yuri-yuri . Some of the volumes are done by Namori herself and others are done by other artists (how it usually goes).
There’s a couple chapters in the manga and in the anime where she gets her friends to dress up in different outfits. I don’t remember the specifics.
But there is also an official spin-off manga and anime movie about Sakurako.