In the fourth act, the sadistic senior is tightly restrained in a straitjacket and leg irons, setting the stage for intense foot tickling torture. With her soles fully exposed, she's subjected to merciless tickling attacks. The senior pleads desperately, crying out "Stop!" and "I can't take it anymore!", vividly demonstrating the effectiveness of the torment. The sensation of complete helplessness while restrained adds a deeply enticing allure, making the tickling-induced ecstasy truly sublime. As she writhes in overwhelming sensation, the scene lingers erotically, tormenting her feet until they turn limp and trembling. This segment masterfully captures the nuanced dynamic between the two, delivering a deeply satisfying and intense experience. Be sure to savor this exquisite scene.