A bouncer/enforcer is asked by his boss to look after his mistress while he is gone. The enforcer is left with strict rules on what to do.
The enforcer falters and is punished by the boss and his mob.
After escaping, he exacts revenge on the boss and all the people who cross him.
This is a intricate view into the life of how korean mobs work.
The action is intense and bloody, but the story does a good job of justifying all the violence you see in the film.
The ending is kind of cheesy, but it does a good job of explaining why the enforcer betrays his own boss.