Mihira Sanpei possesses a Tohou accent and has an optimistic personality with a friendly demeanor. He is a youthful individual who takes fishing very seriously, often putting it above all else. The village where he resides offers diverse fishing challenges due to its natural surroundings. Although inexperienced, Sanpei's keen sense of fishing allows him to participate in various contests and maximize his potential for growth. As he faces numerous obstacles, he learns how to solve complex problems and improve from mistakes, ultimately becoming skilled at catching anything out of the water. Along the way, he encounters both rivals and companions who aid him in gaining valuable experience points and enhancing his development.