Oiroke Event no Oosa ni Teihyou no Aru Watashi desu ga Rival Reijou to Shite no Shimei wo Hatashimasu

Sheri Cassandra is repeating her life for the umpteenth time. Thanks to so many repetitions, she has realized that she is the protagonist's rival lady, the one who is doomed to become degraded by "erotic events." There were times when she thought of escape, but she finally gave up, and now she spends her days fulfilling her mission, hoping for at least a pleasurable end to her life. There are a lot of erotic events, but she's going to do her best to go along with it. That's what she thought, but things seem a little different this time. This is a story about a time-loop villainess who finally finds her happiness. (Source: Comic Gamma Plus, translated) Note: Chapter count includes three volume bonus chapters.