River Of Bondage summary:

"I don't know if you know this, but I prefer play that is a little too hard for a beginner to handle." Seo-ha, a part-time lecturer at a university, is a natural with a temperament. However, because they are afraid of being outed, they have no direct playing experience with a partner. I always yearned for someone to trample on me only in my imagination, and was shocked by the marriage announcement of my senior, who used it as a side dish for masturbation instead of playing, and impulsively looked for a one-night stand in the BDSM community...