On his way to work, Shigeru leads a lost woman by chance.The woman who showed me the way when I came home after work was at her house for some reason.Then she is introduced by her mother to her friend, "I told you that her friend is coming to stay."Shigeru Sumika, who has a beauty that doesn't seem to be her mother's classmate, remembers her heartbeat.Excited and unable to sleep, Shigeru accidentally witnesses the appearance of Sumika indulging in her masturbation when he leaves the room.Shigeru, who was excited by her silliness, pushed her down unintentionally.