"Idaten Jump" centers around Yamato Keisuke, a young boy passionate about mountain biking, who discovers a mysterious parallel world known as X-Zone. This world is inhabited by beings called Idaten, who possess advanced technology and use high-tech bikes called Machine Riders to compete in intense races. The races are not only a test of skill but also a means to determine the fate of the X-Zone, as the Idaten rely on the energy generated from these competitions to sustain their world.

Keisuke is drawn into this world after encountering a powerful Machine Rider named Kiriya, who challenges him to a race. Upon winning, Keisuke gains the ability to summon a Machine Rider of his own, named Shadow. Alongside his friends, including the resourceful Miki and the determined Takeshi, Keisuke becomes embroiled in the high-stakes world of X-Zone racing. The group faces off against various rivals, including the antagonistic Team Doberman, led by the cunning and ruthless Kakeru. Each race introduces new challenges, from treacherous terrains to advanced bike modifications, pushing the characters to their limits.

As the story progresses, Keisuke and his friends uncover the deeper mysteries of the X-Zone, including its connection to Earth and the true purpose of the races. The narrative explores themes of teamwork, perseverance, and the pursuit of excellence, as the characters strive to protect both the X-Zone and their own world from impending threats. The series balances action-packed racing sequences with character development, highlighting the growth of Keisuke and his companions as they navigate the complexities of the X-Zone and its inhabitants.