I don't know if that's right about the digestive system. I'd have to check.
Adequate setup, I guess.
My biggest concern is the category, really. If you're planning to add anime characters, then it won't be an original humor 'fic.
This story seems to stand on its own so far, but if you do decide to go through with it, then you could probably move it to any of the categories for LOTR/DBZ/IY. The foot traffic would be heavier too.