(This review is about the first published version and doesn't take into account newer material.)
I reaaaally like the aesthetics and the use of material from actual historical sources!! The premise is interesting too, and I don't feel too bothered about the story having an original character as a protagonist. Also, the inclusion of Akyuu is so good, never stop including her in yr stories.
I did notice a few consistency issues (the Taikou is dying, seemingly peacefully at the beginning, but then there's a disimbodied voice she's fighting as Tsuyu later on that implies she could go back to her old life as the Taikou. Or was it just her internalized transphobia? That was unclear.) I think this isekai-like story has a lot of potential but I honestly felt like it was emotionally flat, and Tsuyu was too passive -- she seemed not to mind her newfound role/identity too much. I mean, good for her! but I personally didn't find it too compelling, and it contributed to my confusion at the disembodied voice because it came out of nowhere. The pacing issues were mentioned by other reviewers already so I won't get into more detail about that aspect.
As for the romance, I think it was too "oh, you're cute, let's kiss, chu chu" for me and I'm personally unmoved by cute girls kissing other cute girls and doing cute things if there's no reason beyond physical attraction to draw them together. I do enjoy akyuusuzu smooching and I loved that Kosuzu kicked Tsuyu out when she found Akyuu getting intimate with her. But yeah. I think a story like this needs to be longer and to have more dramatic tension. It's the kind of story that is nice to see playing out in posts, where real life people are able to accept themselves with ease, but fiction needs more Contrivances.