Yunika is a beautiful girl who spends every day adoring her best friend Risa, a calm and reserved schoolgirl. Yunika hates her best friend’s older boyfriend because she thinks he is manipulating her. One day, Yunika witnesses a shocking and obscene scene involving Risa and her boyfriend, which arouses intense emotions in her.

Although what Yunika is doing is wrong, she continues her cheating relationship with Risa’s boyfriend, her best friend. Despite Yunika’s aversion to men, she keeps getting involved with that man and giving in to pleasure. Amidst this situation, Yunika, Risa, and the boyfriend plan a trip to a hot spring.