Amid the background sound of a moving train, a dark figure darts through. Its movements seem filled with malice. Inside the sealed carriage, the situation shifts without anyone noticing. Amid mingled breaths, two or more individuals secretly approach, deliberately taking action. Everyone present is drawn into the scenario, regardless of their own will. In this confined space where escape is impossible, just how much humiliation can one endure? The answer will be revealed by the end of this scene.