The story is mostly character driven, yet I think it would benefit more If the author used the fact Fushi knows jack shit about the world to their advantage, instead of just teasing us or give us bits and pieces. Fushi's lack of drive to learn about the world they are supposed to emulate one day also doesn't help, more so since he at some point wanted to grow and learn. It's like he became stagnant and comformed himself with being able to talk, to say smth.
We could be introduced to the different factions of their world and their conflicts in depth now that he has developed to this point yet he choose to strand himself on an island for forty years. I'm still scratching my head over his lack of curiosity over the Yanome that tried to capture him and had one of them kill his friends.