Soshite Haru no Tsuki is a 4 volume gay Shinsengumi manga with imo, the prettiest Saitou art I've seen in any fandom, Hakuoki included. Basically Souji is drawn very...childish/early teenager design and his personality isn't much older than his design. It's also pre Kyoto anything which might account for that.

Well I've got a sort of fail!Hakuoki Hijikata and Kondou, although I've also been back and forthing over Yamanami from Soshite and/or PMK.