Love es M

Mizushiro Ayaka is the protagonist's kind and reliable older sister figure. Tsurutani Ayaka is his girlfriend and a childhood friend. Despite his contentment with both relationships, he harbors a secret and unsatisfied desire to explore S&M practices. He privately acquires related tools for personal use. During one such solitary session, he becomes aware that someone has entered his room and witnessed his secret. He decides to set a trap to identify this person. Upon discovering who it is, an abnormal relationship between them commences.