It's common sense: stay clear of the guy who makes people explode.
Fist of the North Star: Ken's Rage 2 aims to bring to life every bit of the comic it is based on. It tells the story of Kenshiro, an adept of a certain martial arts technique that allows him to do anything to people (from healing, to making them speak the truth, to exploding... but mostly exploding) by hitting pressure points on their bodies. In a merciless post-nuclear apocalypse world where big muscles make the law, Kenshiro uses his skills to protect the weak and innocent.

It is not a complicated story, and while some chapters explore Kenshiro's past and relationships with certain characters, most are simply about him liberating yet another town from yet another band of thugs led by yet another jerk who is somehow not intimidated by the guy who makes people explode with a touch. We see these events unfold in well-done motion comic-style cut scenes, but there are so many of them with so little substance that they become an annoyance. Even the villains with connections to Kenshiro's past turn out to be uninteresting; ultimately, they are just the same as the other nameless idiots you took down in previous chapters. The effort displayed in translating the integrality of the story to a game is impressive but misguided, and the whole thing could have used some editing.
Something also seems to have gone awry during the mission design of Ken's Rage 2. The game is based on the Dynasty Warriors template in which you mow down wave after wave of fist fodder enemies, which offer no resistance whatsoever, to build your Aura meter and unleash a special attack on foes that actually fight back. The problem is, the latter are not only extremely rare, but are also just unsatisfying to fight. Just throw a punch or two to make sure they are not blocking your attacks, press the A button to do a special move, and watch as Kenshiro pummels him. Do this once or twice, and he's done. These enemy "captains" show up infrequently; as a result, you mostly end up mowing down guys with no payoff.
Some, not all, chapters end with an actual boss, and some of those, not all, are actually fun to fight. You have to anticipate their attacks and counter effectively instead of mindlessly mashing the same combo over and over. In other words, they act as what would be regular enemies in any other action game.

And then you have one or two encounters with larger-than-life bosses, titans over three stories tall. But while they may be impressive after fighting a bunch of enemies your own size, the effect quickly fades once you realize just how much of their life bar simple quick time events take away. And even then, that's only when the game asks you to be quick about it: in many cases, it prompts you to press a button and gives you all the time in the world to do so. "Press A to trigger an uplifting guitar riff and watch Kenshiro give some jerk what's coming to him,” basically. I'm no fan of QTEs, but when a game misses their use, that's a bad sign.
The game has a secondary mode in which missions seem better planned and bosses more plentiful, but you have to play the main mode to unlock most of it. These missions are not worth the hours of tedium.
The bloody legacy of Fist of the North Star could have yielded a satisfying, violent melee action game, but intrusive and uninteresting cut scenes, neutered enemies, and repetitious combat make Ken's Rage 2 an exercise in tedium instead. You cannot win against Kenshiro, so just do what his enemies should have, and avoid him.