Welcome Back, Alice 3 (manga)

Yo can't believe his luck – high school’s only just started, and he’s dating Mitani, the girl of his dreams. She tells him to stay away from their other childhood friend, Kei, and that should be easy. Kei might look pretty with his long hair and slender features, but in Yo’s eyes, he’s still a guy.

And yet, when things finally get intimate between Yo and Mitani, he realizes something isn’t right…