Mori wa Nani Iro

Terumi Kai and Shun Minato are great friends. However, their personalities are completely opposite. Kai is an introvert who can't even talk to girls. Shun is a playboy with plenty of experience under his belt. When Yuko Kisaragi appears between them, she subtly changes the once solid friendship between the two men.......! (Source: Shueisha, translated)