One day, Kanae (Mia Masuzaka), an office lady, witnesses a junior suffering damage on a commuter train. Despite Kanae's worries, the junior said, "I was scared at first, but I got wet because I was raped by a beast." Kanae tries to protect herself from the lewdness by tightening the guard, but the beast cannot overlook Kanae's big tits. While being relentlessly tossed on the train on the way back and forth, Kanae's body couldn't be helped without it.