Kim Seokjin works in the FBI. Strange things are happening in Seoul, a gang called Bangtan is running wild and stealing, graffiti and buying/selling illegal drugs. The FBI tried over a million times to catch them but that particular day they got a great idea. Why won't one of their spy's go and join Bangtan? They send Kim Seokjin who willing plays his part until he meets Kim Namjoon better known as RM in his gang. Seokjin hopelessly falls in love. What will happen? Will he have to forget his feelings? Will he ditch the FBI?