Koa, a free-spirited martial artist with un-attended to anger issues, wants to learn all there is to know about martial arts. Traveling to every corner of the world, he spends his adult life seeking training from masters of capoeira, taekwondo, sambo, wing-chun, shotokan karate, and the like. In the end, he settles on one revelation: the best technique is a knockout right-handed punch to the face. It’s on this revelation that he develops his own martial art: “Punch-Fu”. His physical training echoes this revelation, as his body becomes increasingly asymmetrical. His overdeveloped right arm, and hardened fist are icons of his single-minded dedication.

After twelve years of intense training, study, and ‘anger-meditation’ (a from of meditation that channels and magnifies anger into vitality and power), he believes he has mastered combat. He’s developed punches so devastating they break the sound barrier, a heart-stopping punch, one that knocks his opponents literally into next week, and even one that creates a small black hole. He feels he’s now ready to put Punch-Fu to  the test. His method? Return to the masters that originally trained him, and pit Punch-Fu against every other martial art; Whether the masters agree to it or not. In their defeat, each master does their best to impart to Koa the life-lesson he needs to lay hold of: “You can’t punch away all of your problems.

In the course of his challenges, Koa often fights his way through his former masters’ students, with no regard for their well-being. They are simply an obstacle on his journey. Defeating them is a means to an end.

Koa is uniquely alert when entering the final master’s temple. The are of ninjitsu employs not just traditional martial arts, but stealth. The masked disciples prove to be no match for Koa, though one in particular fights more vigorously than the others. After completing his mission, and defeating the final master–On the way out, a masked disciples pulls at his pant leg, then pulling off his mask to reveal that he is Koa’s only son, now a broken and bloodied mess. It’s here where he is confronted with the reality of his success. He proved himself right, at the cost of the one thing he now realizes he cares about more than anything else.

Fast-forward another 22 years. Koa has long given up fighting, though he still trains and works out. He works at the docks as a lumberjack, unable to even begin to forgive himself, but has almost entirely dealt with his anger, through actual meditation. Every day he thinks about calling his now paralyzed son, but fear grips and overcomes him.

Finally he’s able to develop a punch so powerful, it rips through spacetime. He realizes this would allow him to travel back for the real final battle, a duel with himself. There he must find a way to get through to the younger, naive Koa, and undo his greatest mistake.