Musou games are my guiltiest of all pleasures, right behind Justin Timberlake's music and having a certain affinity for the Daredevil movie.
I know. I KNOW. I'm a terrible person for at least two of those three. Nonetheless, there's just something about the systems in the Musou games - upgrading weapons and leveling up. I think it really clicked with me when I got Wei Yun to max level and started doing Chaos runs by SHOOTING A FUCKING FIREBALL FROM MY HEAD! It was just too much fun to be so goddamn powerful when I knew I could get killed so quickly.
With that said, I know jack nor shit about Fist of the North Star. Therefore, I may have to watch some of the anime and manga first before I jump into the game, just so I know what the fuck is going on.
Read at least half of the manga. It's fucking awesome, and the characters are interesting as fuck. Specially Raoh. He's awesome.