A documentary-style work featuring pro 'Morihara Jinen,' known as an expert in anal training, showcasing the process of bringing a woman to climax through anal stimulation. Initially resisting desperately, she gradually loses her ability to endure due to forceful anal stretching. Continued expansion using toys and cocks progressively widens her anus, enabling her to withstand double penetration with two men simultaneously fucking both holes. Eventually, she repeatedly experiences intense anal orgasms, climaxing over and over, depicting her complete transformation.