Years after the last family reunion, relatives gather once again, prompted by the eldest son Takahiro to return to their childhood home. The second daughter, Sayuri, arrives with her husband and young son Masayoshi, while the eldest daughter, Yoshie, comes with her son Ken. However, Yoshie and Ken appear unusually subdued, carrying their luggage with none of their usual energy. Noticing this, Yoshie wastes no time and immediately begins sucking Ken’s cock. Meanwhile, Sayuri’s first night back at her parents’ house ends unsatisfactorily with her husband, leaving her frustrated and restless. Her older brother Takahiro takes her husband out drinking, leaving her alone and sexually unfulfilled—until she finally reaches into her son Masayoshi’s pants. What begins as a simple family gathering quickly spirals into unexpected taboo encounters.