A kid who's cheerful about everything except the one thing he actually cares about. Sanpei flips a switch the moment a rod goes in his hands, and the show respects that intensity enough to build 109 episodes around it. Fishing here isn't relaxation, it's a real sport with real stakes, taught by someone who learned his craft in a village that has nothing else to teach him.

Sanpei is a cheerful, down-to-earth boy from a country village, and nothing matters to him more than fishing. He is easygoing most of the time, but once he picks up a rod he turns completely serious. The natural surroundings of his village offer all sorts of fishing challenges, and he tries every kind of fishing he can. He lacks experience, but he has a sharp natural instinct for the sport and enters fishing contests to make the most of it. His search for new catches takes him deep into the mountains and even overseas to compete. Along the way he meets rivals and companions who help him grow, picks up wisdom from older people, and discovers the wonders of life beneath the water.