Copkiller, Flé-O, Delete, and King Kong swear only by their gangsta rapper tagged caps, baggy jeans, and gold chains. But these West Coast bad boys are in fact Malo, Erwan, Loïc, and Brieuc, four awkward and pimply teenagers who do indeed live on the west coast... but in Plougoumelen in Brittany! The day before summer vacation, Slyvain, a popular student, humiliates them in front of the whole class. But no one fools with their "gang" like that. The four childhood friends decide to go to the party bringing the whole high school together in order to redeem their reputation. Stealing a gun, losing it, smoking their first joint, eluding the gendarmes, never having been so close to a girl wearing only underwear... In one day, Copkiller and his gang will experience their last childhood adventure, one that will be forever engraved in their memories.