Ibon is fourteen years old, he lives in a small town in the Basque Country and his greatest passion is playing football.
He is a midfielder and plays well on the pitch, but one day he discovers something that could end his sporting dream forever: what he has always believed to be offside is actually not.
His team, Sporting de Belako, will win the championship for the first time in its history in the next few games, and Ibon will try to discover for himself what this indecipherable rule consists of.
In this search he will live his first love, he will find secrets that he did not know about his parents and brothers and he will be involved in a good handful of nonsense, both on and off the soccer field.