Sho loved MTB and spent a lot of time practicing at the "X-Zone" practice field with his buddies Takumi and Makoto. Takumi was an excellent technician, while Makoto was a talented female rider. One day, he was challenged by the Samejima brothers' MTB team, "Shark Tooth," to bet the X-Zone. Sho couldn't lose the game since X-Zone was a memorable area where he had spent days with his deceased father. The day came, and while racing with Shark Tooth's leader, black smoke suddenly enveloped them, and they were whisked away to another realm. When he awoke, he discovered Kakeru, Makoto, and his MTB, "Flame Caesar," with him. MTB riders arrived as they were wondering what had occurred. They confronted Sho.