IPZZ-427 Role Reversal! Blackmailing My Big-Titted Sister and Signing a 3-Day Obedience Contract! My Gravure Idol Sister Complains Verbally, But Ultimately Becomes My Exclusive Creampie Pet... The Real Hell Begins Next. Sakura Momo

The story follows the male protagonist who accidentally uncovers compromising information on his busty gravure idol older sister, forcing her to sign a 3-day obedience contract. Though she constantly complains verbally, her body gradually submits, ultimately turning her into the protagonist's exclusive creampie pet. After the contract expires, the true hell begins, as she plunges into an even deeper vortex of training and desire, unable to extricate herself.