I'm not too fond of otome games, but I've taken a liking to Japanese history and Shinsengumi to be precise. This game is not just romance-centric game, but is also aligned to history, for example, you'll notice that if you're in the route where the real historical person survived the war, you'll be living with him with a lot of other people, hence him being alive is aligned to history. Of course rasetsu (Fury) and the whole demon thingy is not there in the history. Nevertheless, they kinda make you think that this is also a possibility somewhere in the history...
Hakuoki: Premium Edition at Google Play market analyse