Love es M

The protagonist is living a seemingly happy life with two important women: Mizushiro Ayaka, a kind and reliable older sister figure, and Tsurutani Ayaka, his childhood friend who is now his girlfriend. However, he harbors a secret hobby that he cannot reveal to anyone: a deep interest in S&M. He secretly buys tools for his personal use, admiring and touching them in private.

One day, while indulging his urges, he realizes someone has entered his room and discovered his hidden secret. Deciding to take control of the situation, he sets a trap to expose the intruder. This leads to the beginning of an abnormal relationship between them, changing everything.