Life with her younger husband was happy at first, but over time, misunderstandings began to grow. One day, Yumi receives a mysterious video. It shows her husband having sex with an unknown woman, prompting her to visit the secret club listed as the sender. There, she discovers her husband's hidden fetish for lotion play. Overwhelmed by the sensation of thick, flowing oil, her body becomes hypersensitive, and she is captivated by the exquisite pleasure of deep vaginal penetration. As Yumi and her husband explore this shared kink, their intimacy grows intense and passionate, leading her to discover new dimensions of pleasure. Behind it all is Mikami Mika, a corporate employee, who—after a chance reunion—guides Yumi into this world of ecstasy, bringing her to climax again and again.