On a small abandoned island with only a lighthouse, you'll find Alberto. Living as a human in the human world, the adventurous Alberto is actually a sea monster who visually appears as a human when dry on land. He's carefree and daring, yet lonely and without friends. That is until Luca washes up on shore. Alberto becomes a guide of sorts for Luca as they explore the human world together, dreaming of one day riding a Vespa! When they meet Giulia, a human girl, their team is complete. They decide to sign up for the local triathlon, the Portorosso Cup. Working as a team, the fear of abandonment appears and friendship takes its place.