Over four days, we explore how far an anal fist can stretch... A record of reaching anal pleasure through expansion development. Subject Rei not only has a physical but also mental affinity for anal pleasure, being a true masochistic anal fetishist. She harbored desires for anal fisting due to her craving for stronger humiliation. As an ideal candidate for this challenge, she volunteered herself as a test subject. This documentary showcases our grueling experiment on female anal maniacs.
