198X, Hong Kong World Karate Championship. Japanese player Hideto Togo was shot by someone and died instantly. Hideto's father, Dr. Naoki Togo, attempted the taboo of "reviving his son's corpse using the power of science,'' and succeeded in reviving Hideto. However, due to the conspiracy of Dr. Gewald's gang, the revived Hidejin has become a monster cyborg with 100 times more power than he had when he was alive.

After many twists and turns, Hidejin is revived and is recognized by the world as "the mysterious superhuman God Arm who fights against Gewald's gang.''