Yui, a young girl with pale skin and an innocent face, is held captive and subjected to the desires of men. Untainted and pure-hearted, she passively accepts training and sensual stimulation. Gradually awakening to pleasure, Yui receives facial after facial from numerous men, her cheeks flushing red with each climax. This facility serves as a cage for training—a hall dedicated to semen, fulfilling its purpose as the Hall of Semen.