Reiko, a single woman working at a general trading company, has a married ex-boyfriend who was also her boss. After being teased by her ex-boss on an empty train car after a company party, she awakens to the thrill of it and starts posting suggestive content on social media with her ex-boss. Awakened to this new pleasure, Reiko becomes addicted to train sex. Her panty-clad ass shakes wildly as she goes crazy! The men, like hyenas, swarm around her sweaty panties, licking and savoring the smooth nylon feel of her ass, thighs, and pussy. "I want you to mess with me more..."