Takeo Aozora, an elementary school student who was first informed that his father, a hero (Abraga), was in Mongolia when his mother died. "Hero" is a special title that refers to a strong man in Mongolian sumo wrestling. Takeo, believing that his beloved mother was once abandoned by his father, "beats" him to Mongolia alone. However, there are harsh trials in the blue land surrounded by vast nature. He is Takeo who wants to live strongly !?