Tsukiha, a female college student, is a healthy girl who makes jogging her daily routine. However, there is an older man named Kita who lives nearby who is always looking at her with lewd eyes. One day, while pretending to take out the trash, Kita bumps into Tsukiha and complains that he got hurt. He invites Tsukiha into his house and before you know it, they start doing lewd things. Tsukiha, who is a natural masochist, is turned on by Kita's greedy sexual acts, and from then on, she is led into a life of lewdness, including with Kita's friend.