Mihira Sanpei speaks with a Tohoku accent and is a down-to-earth boy with a cheerful, optimistic personality. However, when it comes to fishing, he becomes very serious and is a youth who enjoys fishing more than anything else. The village where he lives offers a natural environment that presents various fishing challenges. Despite his lack of experience, Sanpei possesses a first-rate sense for fishing and decides to maximize his potential by entering different fishing contests. As he faces various challenges, he learns to solve difficult problems and learn from his mistakes to the extent that he is able to fish anything out of the waters. Along the way, he encounters all kinds of rivals and companions who increase his experience points and help him in his growth.