Aiji-kun no 15 Toshi Hime ta Shuuchaku Ai ga Fuuka Sugiru.: Kawaii Osananajimi no, Kawaiku Nai hodo Hageshi KobiNew逢司くんの15年秘めた執着愛が深すぎる。～カワイイ幼なじみの、カワイくないほど激しい交尾～; Aiji-kun's 15-Year Hidden Obsession Is Too Deep: My Cute Childhood Friend's Not-So-Cute Intense Love

Natsume Miyahara is an office worker who has been struggling with her sexual desires. When a coworker suggests trying a service for women, she casually mentions it to Aiji Kawai, her five-years-younger childhood friend and a popular nail artist. But Aiji, whom Natsume has always thought of as a cute younger brother, offers her another option: becoming intimate with him instead. As she begins to see the mature man he has become, Natsume realizes that Aiji has been hiding intense feelings for her for years. What she doesn't know is that his affection has grown into a deep possessiveness that he can no longer keep hidden. Their relationship takes an unexpected turn as her longtime childhood friend finally reveals just how strongly he has desired her.