Eleven-year-old Alfred is the son of a mathematician and is constantly being bullied by of his fellow-pupils. One of the youths' ring leaders is Benny, who begins to take an interest in Alfred when he discovers that he is good at drawing. Benny's father, who is also called Benny and runs a gym, has tattoos all over his body. Young Benny wants to have one just like his Dad's, and he asks Alfred to tattoo it on his right arm. This marks the beginning of a wonderful friendship during which the two boys steal a moped, raid a kiosk, go to a disco and do all sorts of dangerous things that Alfred would never have done alone.