18-year-old female student Yuu secretly visits her maternal uncle, a man known to no one but herself. He is a renowned "rope master," a figure of deep significance to her. This relationship, hidden even from her mother, transcends mere familial bonds, pulling her into a dark, twisted vortex of desire.
Suddenly bound by his ropes, she struggles to breathe, yet within this first experience of bondage, she feels an alien excitement—something she's never known before. She senses herself as a warped, forbidden fruit, trembling with these unsettling emotions. Under his "binding," her femininity gradually awakens, consumed by inner desires she can no longer suppress.
Her mind overtaken by grotesque yearnings, she bleeds yet becomes intoxicated, immersed in days of sensual ecstasy. Now, she reacts hungrily to his ropes, descending deeper and deeper into his torment as a beautiful mature woman.
The fusion of taboo and erotic beauty in her uncle's "binding" grows increasingly severe. Yuu's mind and body can no longer withstand his torment. Falling into the depths of depravity as a gorgeous beast, she surges forward into a new realm of existence.