Yuka Ootori, a freelance journalist, investigates unsettling incidents tied to a late-night train. She pursues leads by attempting interviews with individuals named Tetsuo, Makoto, and Inoue, all of whom deny any knowledge. Facing obstacles due to lack of cooperation, she escalates her investigation toward higher-level management. When her article stalls, she undertakes risky undercover surveillance aboard the train—controlled by Tetsuo. Her curiosity leads to unintended consequences: engaging in sexual activities with passengers, recorded without her consent. Tetsuo initially plans blackmail using these recordings, but this becomes unnecessary when she unexpectedly derives pleasure from the encounters. Yuka possesses aubergine-colored hair and violet eyes.