"The Heir to the Namgung Clan is a Rogue?!" Namgung Cheon, the head of the prestigious Namgung Clan, discovers the existence of his long-lost son and assigns a bodyguard to bring him home. Unbi, suddenly confronted with the revelation that his biological father is none other than the head of the Namgung Clan, agrees to go with them after being promised the chance to grow stronger. Upon arriving at the Namgung estate, Unbi finds himself in a rivalry with his half-brother, Namgung Yeomwoo, for the position of the heir. "The sword techniques of the Namgung Clan? Who needs those? A real man fights with his fists!" Armed with nothing but his fists, Unbi embarks on heir training, facing off against powerful opponents he never encountered during his days as a rogue. A thrilling new adventure begins!