Luka is twelve years old, he is cheerful and curious... a sea monster! But, like any ordinary boy, he wants to make friends and get to know the world. True, this can only be done on land, and he is forbidden to go there, even though he knows how to turn into a person... Everything changes when Luka meets Alberto, another sea monster, who - wow! - lives on an island. And very soon the boys will go to the mainland - to the town of Portorosso - to fulfill their dream: to go explore the world on a real Vespa. There is only a small problem - just one drop of water, and the sea monsters will be exposed, and then they will be in trouble! And there is more than enough water in the coastal town...