Kabashira Baku, who came to Tokyo from "Bakuotoko Island" beyond Okinawa to earn money for his younger sister Kasumi's surgery, met Naoko, a researcher at "Kazama Sports Research Institute", who expected him to have extraordinary physical ability. If he wins, he will participate in an obstacle race with a prize of 3 million yen as a temporary player. Explosion, who only wanted to win even though his body was rattled by the extreme race, came up with a secret plan...? A classic action sports manga depicting boys and girls aiming for a national triathlon tournament!