Sho Yamato enjoys MTB riding (short for "Mountain bike") a whole lot, he's always practiced at the X-Zone with his friends, Kakeru and Makoto, on a bike his dad has built called 'Flame Kaiser'. One day, he was challenged to a race by a MTB team called Shark Tooth and whoever won the race got the X-Zone. For Sho, the X-Zone had always been a place of happy memories. He had spent many days there with his father who had disappeared, so he could not lose the game. During the race with Team Shark Tooth's leader Gabu Samejima, black smoke suddenly covered the ground around them, and they were sent to another world that's also called the X-Zone. When Sho woke up, he found Kakeru, Makoto, and his MTB Flame Kaiser were also there. Of course, they did not know where they were... While they were wondering what had happened, MTB riders came. They challenged Sho to a Idaten battle, a form of MTB race in X-Zone. They said the only way for Sho to return is by collecting 10 gold emblems by winning Idaten battles. This is how Sho came down to compete in Idaten Battles at various courses, such as ghost towns, volcanoes, ancient ruins, deserts, and snow-topped mountains. Now Sho must Idaten Battle for the sake of returning home.