Musashi lives with his father. His mother left them three years ago, but Musashi believes she will come back to them. One day they move from Tokyo to a village in the countryside. Musashi hates living in the countryside and asks his father to take him back to Tokyo. He wonders if his mother will be able to find him in their new home.

Soon after moving to the countryside, Musashi happens to see a man fishing for bass with a decoy fish. Musashi is fascinated by lure fishing. He learns a lot from the man, and discovers that his mother's father was a grand champion of bass fishing. Musashi feels that fishing could lead him to his missing mother. He shows a marvelous talent for lure fishing and takes trips with his friends he first meet, Mio and Suguru to many places around the world in search of various incredible fish. Through fishing, Musashi comes to enjoy living amongst nature.

(from http://en.wikipedia.org)