妹が”義妹”ってことを俺だけが知らない〜双子の美人姉妹は何も知らない兄を堕としたい〜 (Associated Names)

Otaru Yuto’s younger sisters are the most talked-about beautiful twin sisters in town. The twin sister, Otaru Yuri, is an honor student, and the twin sister, Otaru Kairi, is a blonde-haired gal. One night, the beautiful sisters overhear their parents talking in the living room about the shocking fact that the twin sisters and Yuto…