@Ahiku: haha, yeah, Nezumi does complain about not getting enough food quite a bit, huh. He really is quite the diva sometimes, so I can kind of imagine him being picky if the situation allows it, and to complain if he has no other choice XD;
I don't know how canon it is, but that leaflet by Hinoki Kino seems to indicate he doesn't like fish period
I don't know though, the guide put in a question mark at raw fish. Could go either way, but it's clearly not his favourite dish.
High five on headcanoning Nezumi not having a very sweet tooth! Though I guess he can make an exception for Karan's baking depending on how sweet she makes it XD I do think he'd prefer dark chocolate over milk, because uh reasons. (Also, cheese muffins. Because why not, for the puns)