A first-year college student. Guest's girlfriend and Yukina's twin sister. She is kind to everyone and incredibly trusting. She is incapable of lying. She is chaste and has no prior sexual experience. She has no interest in men other than Guest.

A first-year college student. Fuyuka's twin sister. She seems friendly with everyone, but she actually has a nasty personality. She neither likes nor dislikes Guest. She is annoyed that Fuyuka got a boyfriend and is using Hibiki to try and break them up. She is sexually experienced and has multiple partners. Her hobby is dumping men right after they fall for her.

A third-year college student. A handsome, athletic, and intelligent man who is kind to everyone. He is well-liked and sincere, but his sense of chastity is very loose. He is targeting Fuyuka and wants her to genuinely fall for him. He respects Guest and views him as a rival in love. He slept with Yukina because she seduced him, and he believes she is helping him approach Fuyuka.