It's a really good shounen manhwa of 12 volumes.

Jo Pae, a not really sane boy, in our modern days, he wants to become emperor of Korea... His first step when he enters high school is to become the leader of the strongest school there is. No one expecting it, he actually takes down all of the school's yankees. Jo Pae is now the enemy to kill! All rival schools wants his head whatever the means!

From mangaupdates



• Associated names : 발작, Bal Jack, Bal Jak, Baljak.
  
• Manhwaga : KIM Young Oh.
  
• Scenarist : JEONG SANG Youn ( not for the end ).
  
• Year : 2000.
  
• Genres : action, comedy, shounen.

This serie is pretty good and cool, it's one of the best shounen manga for me ;)