Three children from Watermill Village plan a mountain picnic. Pico, a young hamster, is eager to reach the peak with friends Tocho and Fufu. While exploring, the trio falls into a hidden lake beneath the mountains and encounters a giant fish named Aesop, who floats in the water. They learn that Aesop wishes to fly again, and to help him they must gather mystical scales scattered across the world. Thus, they set out on a quest to collect these scales and fulfill Aesop's dream.