Asuka and Rika are cousins. They used to play together often as children, but lost contact after Asuka's family moved to Tokyo. After graduating from college, Rika decides to work in Tokyo, and with no place to live yet, she stays at Asuka's house. Reuniting after so long, the two quickly grow closer and their bond deepens. Rika is actually a lesbian, and as she sees how much Asuka has grown, she finds herself increasingly attracted to her. Their relationship continues to intensify.