【sake bottle】Inversion

The protagonist is in love with his older childhood friend, Chiharu. But because they grew up like sisters and brothers, even now that they’re lovers, they’re still treated as if they’re younger. In the midst of all this, he receives a reward for passing the university entrance exam. I want to be recognized as a man by my sister Chiharu! After thinking about it, the protagonist comes up with a request for a “reward": a date with a rotor. It’s a great way to get to know your older girlfriend, and to turn on her sensitive switch and take over her erotic mount! You’ll get a real hard-on in the fitting room! A secret date of extreme embarrassment!