Ryo, a mathematics teacher, encounters a molester on her commuter train. Her serious daily life, discussing educational theories with a colleague's husband, is suddenly disrupted... In the cramped space of a crowded train, her body cannot resist the true pleasure she experiences for the first time. Before long, the formulas of reason Ryo once held melt away, and she transforms into a lewd teacher who squirts while stifling her voice right next to her husband. Longing for the days that satisfy her secret carnal desires, she boards the violently shaking commuter train again today, seeking forbidden in-train training...
