Shota, who tends to be a recluse, opens Kokoro to his only friend, Terumasa. When Terumasa goes to Shota's house to play with his sister Rina, Shota becomes interested in Rina's large breasts and starts to play with them little by little. Although Rina resists at first, she gradually accepts the pranks, saying, "If it will cheer Shota up,"...