Nyan Koi!

The hapless hero of Nyankoi! is Junpei Kosaka, a guy who not only hates cats, he's deathly allergic to them. So it's kind of bummer that he has a crush on a classmate who adores kitties, and things go from bad to worse when he accidentally angers a guardian deity of cats who bestows upon him a gift and a curse. He can now understand what cats say, but he must grant 100 wishes from cats or he'll be turned into a cat himself!

(Source: CMX)