On Seiran Island, secret society NLNS is united by Junnosuke Tachibana, who is determined to crush a law. They have found a benefactor, an unknown rich man, who offers them a secret base and cash. Their mission is to locate a mysterious girl and stop the law, keeping the SHO off their trail.

Nagato Shinobu is a simple student who all of a sudden finds himself in deep when the most popular girl in class, his childhood friend, and an old unrequited love all confess to him at the same time! His eroge-filled youth is about to begin!

Tooru documents his irrepressible erotic fantasies in his "Fetish Diary". Writing in it both helps him repress his insatiable lust and serves as a way to get himself off in a way other than mere masturbation. Then, one day Tooru forgets his Diary in the classroom so he hurries back to pick it up, but what he finds is his classmate Ootori Chikage masturbating while reading his diary.

Hinata Sakurai, an ordinary girl with a secret identity as the Magical Girl Saint Lime, fights against the Viest Army to rescue her missing brother, who once was the heroine Saint Cherry. Now corrupted and transformed into an evil magical girl, Cherry has become her greatest challenge. With the power her brother entrusted to her, Hinata turns her sorrow into rage to save him, facing a great evil while discovering her true desire and nature.