A young salaryman’s routine train ride takes an unexpected turn when he is wrongly accused of misconduct and pressured into a confession. Seeking the real offender, he confronts the culprit and learns of a secretive discipline known as Chikan-do. Impressed by his determination, the man accepts him as the 500th apprentice, introducing foundational strategies that promise to reshape his understanding of everyday encounters. Thus begins an unusual journey of skill and perspective.