Driven to the brink by unrelenting torment, Ha-Je Kang finds himself teetering on the school rooftop, contemplating a tragic end. In a twist of fate, a cryptic senior student, Si-Un Lee, intervenes just in time, unwittingly saving Ha-Je from a fatal fall. To Ha-Je's astonishment, the next day dawns upon him unharmed. Unbeknownst to Ha-Je, Si-Un is a renowned warrior in the clandestine realm of Murim, the domain of martial arts. Desperate for guidance, Ha-Je implores Si-Un to mentor him, thrusting himself into a world of martial arts fraught with unforeseen challenges and dangers.