Board Thread:Questions and Answers/@comment-66.87.79.104-20140714071241/@comment-62.65.156.2-20141013110054

Nitori being a remora fits him perfectly. I mean, the more you look at him (his behavior, relationship with Rin, the contrast between the great "Rin-senpai" and his much weaker self for instance...) the more it seems clear.

I also initially thought his animal's a duck, for the same reasons as stated above. Or a chicken. (Nitori <-> Niwatori) He always striked me as a bird somehow.

Seijuro is much harder to type. If X's animal is relevant to his height then yeah, some kind of whale would be plausible since he's one of the tallest of the cast. But he's probably a marlin... I guess we'll never find out anytime soon.