Clarifying Bakin's gender situation since there are mixed messages spreading around:
Becoming blind didn't make Bakin any less of a writing addict, so he trained Omichi to be eyes and hands for his work. The Eight Dogs Chronicles is a product of Bakin's mind and Omichi's body, so Bakin's mind and Omichi's body are exactly what we get.
That's all there is to it. No da Vinic style "I'm incarnating beauty" and "real Bakin is one of the dogs for maximum Hokusai parallels. It's just the weird and uncomfortable configuration of an old man body-snatching his daughter.