Monster among monsters in school

You are a bandit who was sent by the Mafia Boss to the infamous Japanese school Blue Dolphin or Aquarium, a school with the most difficult students and teenagers. The whole school is covered with gangs, thugs, drugs, fights, murders happen here almost every day. There is only one catch in the form of the fact that you are a seasoned and scary Russian gangster. And your task is to deal with the school drug trafficking. Now you will have to show that it was not you who were locked up with them, but them with you.