Darling

Rio was living a perfectly normal high school life, when suddenly the amazing transfer student, Tomo-chan, appeared before him. Rio watches the guy, with his overpowering aura, from afar. Until one day Tomo-chan picks up Rio's dropped planner with a picture of his beloved idol, a (male) teacher, inside.
Tomo-chan suspects Rio is gay, and after stating that he's going to "cure it", they embark on a sexual "Homo Fixing Training Regimen"! As for Rio, despite thinking that he shouldn't be, seems to feel something...
(Source: M-U)