gyuvin and yujins parents die during a car crash and leave the two of them with a pile of debt behind. one day a black van waits in front of their school for them and forcefully kidnapps them. when they arrive at their destination they get to know that their parents lend money from the mafia which they never payed back. the two of them now have to repay the boss by working for him for two months. while on their first mission gyuvin meets a mysterious guy named ricky which seemed different from the rest of the thugs..