After a massive earthquake rocked the Kanto region of Japan, the landscape remains decimated and towns of survivors are few and far between. One settlement dubbed ‘Hope Town' has previously been kept safe from invaders and danger, but one day the infamous Hell's Wind biker gang rolls into town. Known for being brutal and merciless, they quickly lay waste to the buildings, capture all of the townspeople and get set to rape a woman named Keiko. However, at the last second a badly-scarred, battle-hardened Jun appears; Hell's Wind previously had captured her and her boyfriend, viciously murdered her love and raped and left her for dead. Now, Jun and an unlikely companion - the giant Violence Jack - will try to put a stop to Hell's Wind and rescue Keiko!
In a post-apocalyptic future, gangs of savage thugs prey on the fleeting remnants of civilization, raiding them for food and water in the endless wasteland the world has become. Humankind's only hope for the future may lie in a young girl with an amazing ability and in the only man powerful enough to protect her and punish evil--Ken, the Fist of the North Star!
Both take place in a post-apocalyptic world where people are terrorized by evil biker gangs and others who torment the weak. Both anime are very violent and gory, though Violence Jack 3 has graphic rape and attempted rape scenes that are not in Fist of the North Star. Also, both anime have a similar feel, in my opinion. If you like one, you may like the other.