Kakyuusei 2: Anthology (2006)

Childhood friends, Rouma and Tamaki, are not just friends. Actually, they have sexual intercourse, but they're not lovers, either. One day, Tamaki gets angry with Rouma and announces to break with him because he didn't take contraception measure while they were doing things. However, because they belong to the same club, they have to meet. Seeing their cold attitudes, Yuuri tries to make them friends again. However, she can't hide her love toward Rouma, and confesses her love. Then, they make love, but... (Source: AnimeNfo)