Alterna(2007)

Alterna

"I feel like this jealousy is going to burn my insides up." Miki Sasaoka is a freelancer who has a crush on his childhood friend, a college student named Keisuke Takeo. But Keisuke isn't a guy who likes other guys... Or so Miki thought, until Keisuke is revealed to have found a guy he likes! "I'd rather steal him than have him stolen from me!" And so, Miki tries to take the person Keisuke likes away... It's a romance survival adventure hidden in daily life!

(Source: Renta!)