Chan struggles to lead a subunit group of antiheroic assassins, but someone's got to do it. Then he stumbles along Felix, a reckless kid who has a lot to prove. Minho is trying to keep a stable "friendship" with Jisung, who wants something more. I.N is madly in love with Hyunjin, completely unaware of the feelings Seungmin holds. In other words, nine boys grow up too quickly in a world not made for them.