N, Leo, Hyuk, Hongbin, Ravi and Ken are all in college. N owns his own apartment with Ken, Hyuk, Hongbin and Ravi living with him. When someone moves out and there's a spare room left, N puts up posters saying there's a spare room in his apartment if anyone wants to be roommates. At the same time Leo leaves his parents house, convincing them that he's old enough to live on his own and just so happens to pass by one of the posters N had put up. Leo ends up moving in with the five other boys until N gets very curious about Leo's past because of his quiet and unique personality.