ROYD-338 — 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. - Sato Airu

My parents remarried, and suddenly I have a stepsister. She's incredibly cute. And she's quite timid. She's easily influenced by others and very weak to pressure. So, I decided to tease her every single day, day after day. In the morning, at noon, when she's sleeping, when she's taking a bath... And guess what? She's started asking for teasing! She's become such a perverted girl that she can't live without it. But she's also grown into a girl who can express her own opinions clearly, even saying things like, "I want you to touch my nipples."