Chulería is a fantastic Spanish slang word that means a kind of effortless cool, swagger, or charming cockiness. It's the special flair that makes someone stand out.
In the song, the main character Diego is described as having "chulería y ese punto de alegría" (swagger and that touch of joy). This single word perfectly captures his magnetic personality as he confidently walks into the club, ready to take over the dance floor.
Meet Diego, the star of Las Ketchup's monster pop track. When the clock strikes midnight, he steps right into a packed club dressed in an aquamarine suit ("su traje agua marina"), sporting moonlit eyes ("con la luna en las pupilas") and leftover party residue ("restos de contrabando"). The song describes him as an "afrogitano" (Afro-Romani) with a cool swagger ("chulería") who squeezes into the tightest spots on the dance floor ("donde más no cabe un alma") just to go all out ("darse caña").
The DJ spots him immediately and drops his favorite track, "el himno de las doce" (the midnight anthem). Diego gets swept up in what the song calls the "ritmo ragatanga", belting out the chorus: "Aserejé, de je, de jebe tu de jebere". It is pure gibberish, meant to mimic how a non-English speaker tries to rap along to an English song at full volume in the middle of a noisy club. He dances, enjoys himself, and sings at the top of his lungs without caring if the words make sense.