Kim Hyun Joong is the leader of the biggest mafia ever. His four sisters formed they're own little gang and they all live together. They harbor all on the run gangs and mafias. Five undercover agents enter the house posing as a gang known as big bang. But when they're leader Gd begins to fall for one Hyun Joong's sisters, he begins to find complications with completing his job. Will he be able to keep it from her or get found out and killed?

Min Youngee and Kwon ji-yong where high school sweat hearts. Kwon proposed and Min of course said yes. But after a visit to the doctors, she finds that she has brain cancer and that it can't be cured. She knows this will destroy him. So she gets T.O.P to pretend that they cheated. All his friends know what's going on and agree having him angry would help him heal faster. But can they keep the act up?

Jiong is the leader of a powerful Mafia. Other mafia members are jealous of his power and believe he doesn't deserve it. They have tried to convince him to hand over the mafia but he refuses. And after they went after his sister to get to him he decided it was best to shield himself from love. But will someone change his mind?