I don't know how else to narrow it down so I'll just mention a few things, maybe someone will know what I'm talking about.

I couldn't tell you if its Manga, Manhwa, or Manhua, but it was about a delinquent called (i think) Jo Pei. There were also two other supporting MC's and together they formed a motley crew.
The first 3 chapters are from the perspectives of these three character. You've got Jo Pei, who thinks he's invincible and the only person who can beat him is himself. He behaves in a wild and unrestrained and criminal manner, going so far as to kick an upper classman off a rooftop and beat one of the other MC's unconscious before stealing his clothes and shoving a pipe up his ass.
The second MC is a bit of a skirt chaser, he gets himself a nice new coat for his first day of high school before encountering MC1, who as mentioned above, beats, strips, and assaults him.
The third MC is a bit of a weird one, indifferent and cold, he seems to disdain the way people behave in 'polite society'. He soon finds kinship MC2 (when he finds him hopping around in the street trying to pull the pipe out of his ass) and MC1 (Jo Pei, when he kicks an upperclassman of a rooftop).

Somewhere in the first few chapters, Jo Pei graduates from Middle School to High School and commemorates the moment by beat the crap out of himself at the graduation ceremony.

Not sure what else I can do to narrow it down... Its not new, I read it a few years ago at least, but it was one of those things that you put on the back burner and tell yourself you're gona read, yet never do.