Ahh, FIST OF THE NORTH STAR! I remember this from the early splatter movie days in the early 90s. I still have my old English dubbed VHS from Manga in the UK. FIST is finally gonna be released on DVD with its original Japanese dub soon (there was another reg.1 DVD ten yrs ago, but it only carried the Eng. dub). More here.
[from Nippon Cinema site]
In the post-apocalyptic near future, Earth has been utterly devastated by nuclear war. Only the strongest survive in this brutal landscape, and Kenshiro’s inherited “Hokuto Shinken” style of fighting may make him the strongest of all—allowing him to cause spontaneous implosion in his enemies after his blows have landed. Unfortunately he is betrayed by his best friend Shin who uses the “Nanto Koshuken” style to carve 7 scars in Kenshiro’s chest, leaving him for dead and stealing his girlfriend Yuria. Many months later a cloaked figure appears, making gangs of super-powered lunatics seem like weaklings in comparison to his fighting skill. Kenshiro is back even stronger than before, and he’s not going to stop until he’s taken back what’s rightfully his.