Himari and her childhood friend Takumi and Shinji often go out drinking together, and when the two get along well, she confesses her feelings to him when Takumi isn't around, and he accepts her confession and they start dating. But that's just the beginning of a nightmare. Shinji is devastated by the fact that Himari is Takumi's sex friend and that she orgasms more than he does with her, but his erection never goes away.