Synopsis: Osananajimi no Ijou Kawaii Imouto-chan

幼馴染の異常可愛い妹ちゃん / My Friend's Abnormally Cute Sister / 发小的异常可爱的妹妹 / 发小的巨可爱妹妹 / 發小的異常可愛的妹妹 / 發小的巨可愛妹妹 / Cô Em Gái Dễ Thương Nhưng Lạ Thường Của Bạn Tôi Yanagi, a second-year high school student, has a faint crush on Mizuki, the younger sister of her childhood friend Momo. One day, while rummaging through Mizuki's personal belongings in her room, Yanagi discovers the truth about Mizuki...?