Boku no Kawaii Doutei-kun

Akihiko Nakajima, a college student who's never had a girlfriend, meets Asahi through a private tutoring job. With sparkling eyes and flowing hair, his pupil is prettier than any girl. Akihiko, who's still a virgin and has trouble talking to girls, finds himself strangely drawn to Asahi despite knowing he's a boy. One day, Asahi tells Akihiko that he's embarrassed to use the showers at school and asks if he can see what Akihiko looks like. Reluctantly, Akihiko agrees... but the angelic young boy turns out to be a relentless devil!

(Source: Renta!)