High schooler Kenichi Shirahama juggles karate club beatdowns with his self-help book obsession until a chance encounter with new student Miu Furinji changes his fate. When faced with a club ultimatum, Kenichi's world shifts as he witnesses Miu's prowess and seeks martial arts guidance at her grandfather's eccentric dojo. Entering a dangerous realm of martial arts with the looming Ragnarok gang, Kenichi embarks on a treacherous path to strength and protection.