Also known as: 美少女万華鏡-罪と罰の少女-
Bishoujo Mangekyou: Tsumi to Batsu no Shoujo (Girl of Sin & Punishment), the fourth game of the series follows Kannagi Yuuma, who is on leave from school due to being hospitalized in an incident. For the first time in a year, he finally reunited with his beautiful twin sister Kannagi Yuuri and began living with her. However, he has a secret that he cannot tell his sister: he is genuinely in love with her.