Still doing my best to try and give a shot at most of the ones mentioned here and thoroughly finding that I have no time to do so, but I picked up a volume on a brief recommendation from my favourite manga site, Spectrum Nexus. Tossing it out there to see if anyone has heard of this one or perhaps to see what anyone else thinks:
Simple plot line: Ken Rock is a guy in Japan is pretty much a nobody, loves a girl who, for inexplicable reasons, bolts to Korea to become a cop. He decides to follow her there as well and continues to be a bum. (don't worry, this all happens within the first few pages) He meets up with some thugs who want to start a gang, or nation, and soon recruit him as their leader and all Ken Rock decides is his goal is to protect people with his strength... which he does by bludgeoning them with a baseball bat or kicking their heads in. The plot unfolds pretty much as you'd expect after that.
Now, all this is really funny to write because it is so much like a Naruto style plot line and the story unfolds with fights and over-the-top shonen style humour - you know, the yelling, bawling from the eyes and insane reactions. But the rest of it is so dark and violent. In the first volume, there is a scene in which the group celebrates the formation of the gang in song and dance and then a few chapters later a rival group is holding down a girl they know and raping her. Seriously.
Not for those with adversion to blood, sex and not so kind scenes involving implied or unshown violent rape (one character is especially done in horribly by the author) yet, it does seem to flow easily. Oh, and there is a female introduction who can kick as but seems to have an adversion to pants. I don't understand it, but there it is.