A threesome must include my sister

In order to inherit the will of his father Teino Kumagoro (voiced by Oyama Rikiya), high school student Teino Shogo (voiced by Sakurai Takahiro) entered the aristocratic school Shenryuin Academy to learn how to become a qualified president. Not only that, in the next two years, Shogo must also find a marriage partner in the academy who can be entrusted to his life. This stumps Shogo, who has an ordinary personality. However, nothing is difficult in the world, and Shogo's happy high school life is about to begin. On his birthday, Jiang Wu received a call from a girl who claimed to be his "sister". However, Jiang Wu had no clue who this sister was. In the academy, Shougo got to know many cute girls, including the class committee member Tsuruma Shinoji (voiced by Ishihara Kaori), the silent and shy Kami Nagiya (voiced by Sakura Ayane), the high-IQ girl Saga Ryo Mei (voiced by Hidori Rina), and others. And Shougo felt that the mysterious sister was hidden among these girls as soft as flowers.