After enduring relentless bullying for most of his life, 17-year-old Yu has grown emotionally numb and detached from reality, losing the ability to behave like a normal person. Despite having the rare talent to dodge punches, Yu allows his attackers to beat him, finding no purpose in his own survival. His situation begins to improve when Yu encounters an elderly boxing trainer known as "K." Having trained five champions, K’s extensive experience and sharp intuition enable him to instantly recognize Yu’s almost superhuman fighting potential. K moves quickly to take Yu under his wing, even though Yu shows no apparent interest. Yet, after recalling a vivid memory from his past, Yu changes his mind and accepts K’s offer, hoping to feel that same light again. Consequently, Yu steps into a world filled with powerful opponents—both righteous and monstrous—and for the first time, he is forced to fight back.