I'd heard of Enomoto Takeaki and the Republic of Ezo, because I was obsessed with anime and manga about that time period for a while
Oh, neat! We're still about 50 years earlier than the period I'm familiar with, so it was new to me and I'm fascinated by the alternate-history possibilities. Let me know if there's anything I should be reading/watching...

the sources I read didn't mention Tatsu. And they should!
Seriously! I can't pin down whether she was in Hokkaido with her husband or still back in Tokyo, but either way.