ROYD-318 My innocent and extremely shy stepsister became super sensitive and prone to premature ejaculation after I harassed her every day, and now she's orgasming like crazy! She transforms into a perverted girl who orgasms like crazy with a vulgar look on her face. - Ayatsuki Nanao

My parents remarried, and suddenly I had a stepsister. She's incredibly cute with a pure, innocent look, and honestly, I wanted to do something about her. My stepsister is quite shy, easily swayed, and a timid coward who can't express her own opinions. So, even though I touched her nipples every day from morning till night, she didn't complain at all. In fact, she started to feel pleasure, even drooling and trembling in response... Her nipples became more and more sensitive, and eventually she would even come over to me and ask me to touch them. Even though she has a boyfriend! What a pervert.