Toko and Yuki are mother and son, yet they have developed a physical relationship. After Yuki gets a job and leaves his mother's home, Toko continues to see him as the man she loves most. One day, she receives a message from Yuki saying, "I've got a girlfriend," triggering intense jealousy within her. Unable to bear it, she tells him, "Come see me again after all this time," and summons Yuki to a hot spring inn.