Hibiki, a housewife who is bored with her boring daily life, starts working part-time at a convenience store in an attempt to change the situation. At first, she rejects the advances of her younger coworker, Hayashi, who she meets there, but she begins to accept him because she is lonely and not getting along with her husband. Although she feels guilty, she becomes addicted to extramarital sex with Hayashi, who is young and has a big penis, and falls into a life of carnal desire...