Based on Kusano Kouichi's online manga serialised in the web comic magazine Web Comic High!.
Takanashi Shuusuke has a predilection for collecting pornographic books, DVDs and pictures.
Nao is Shuusuke's younger sister. Rather than a cool older brother, she prefers the lewd older brother who desperately attempts to get a glimpse of her panties.
One day, Shuusuke's childhood friend Tsuchiura Iroha, whom he had not seen for 10 years, appears before the two and immediately throws herself at Shuusuke.
Thus, Shuusuke finds himself in a love triangle with Nao and Iroha.