20 years ago, slacker Diego used to make quick cash by regularly donating his sperm under the nickname ‘Fonzy’. Fast forward 22 years and Diego still lives like a fun-loving teenager. But when his girlfriend Elsa announces she's pregnant, his past starts to catch up with him. Diego discovers that he's the biological father to 533 children, 142 of whom want to know just who this 'Fonzy' is.