Hyunwoo has recently been debuted as the leader of MonstaX. His fame and recognition has left him sedated until he meets the crazy "Mouse" (Mona Yeun). A tiny girl who packs a punch with monster like eating habits and the gift of not know who he is and the life he leads- The ordinary Mona has the attitude of an old person with eating habits of villagers but manages to be the only person Hyunwoo can breathe peacefully infront of.