「Strong Masturbation」 In her room, Sumire Shirakawa starts strong masturbation according to the instructions of Professor Kurahashi's email... Masturbating while thinking about the teacher leads to a pleasure she has never experienced before... "Group Humiliation Play!?" Following Professor Kurahashi's instructions, Sumire, on the train, takes off her clothes. Enduring the embarrassment, she exposes her chest and sends a photo... But her blunder is discovered by her classmates, and group humiliation play begins at school and on crowded trains...!?