Description:

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...?

Alternative Titles:

幼馴染の異常可愛い妹ちゃん, Osananajimi no Ijou Kawaii Imouto-chan