Shinya and Mizuki are so close that they know everything about each other, from their love affairs to their propensity, regardless of gender. At a drinking party with a group of good friends at university, Mizuki, who is usually strong, quickly collapses and decides to stay at Shinya's house. Mizuki's frank talk that it seems that he accidentally had sex with one of his close friends and it seems to have become embarrassing, but...! ?