After divorcing her husband, Shizuko raises her only son Kouta alone. She returns to her hometown and decides to start anew, but she worries about whether the introverted Kouta can make new friends. Such a Kouta joins the baseball club and starts making more friends, but in reality, these seemingly friendly acquaintances are after Shizuko's large buttocks. One day, while Shizuko is trying to insert a suppository and has her anus dilated, she is spotted by Kouta's friend 'Shimiken,' who begins inserting his fingers into her anus...
