It is a year since Taiki Kudō's adventure in the Digital World as he forms the “Xros Heart” basketball team together with Yū Amano, who became his junior at his school, and Tagiru Akashi. However, on his way home from game, Taiki sees a monstrous shadow within a space fluctuation before being confronted by three children. The leader of the trio recognizes Taiki and his potential but tells him not to meddle in their affairs before leaving. The next day after school, Tagiru hears a voice begging to be saved, and after seeing a spacial distortion, Tagiru gets dragged right into it and ends up in a Digital World like dimension called the DigiQuartz, where time flows differently to the real world. Tagiru sees the source of the voice, Gumdramon bring attacked by a MetalTyranomon until the three children arrive and fight it with their Digimon, but it escapes from them. After being told they are Digimon Hunters, Tagiru wants to be one too as he is told to get a X Loader first. Teaming up with Gumdramon, Tagiru heads to the home of the Old Clock Store Owner and receives a crimson X Loader from him. Taiki and Yū find out about the rampaging Digimon and when they see Tagiru warping into the DigiQuartz, they decide to follow him. Tagiru and Gumdramon fight a losing battle with MetalTyranomon until Tagiru learns to Super Evolve Gumdramon into Arresterdramon and defeat it. After capturing MetalTyranomon's data into his Xros Loader, Tagiru sees Taiki and Yū, who are branding their own X Loaders, much to his surprise, but before they start to talk about the situation, Shoutmon contacts Taiki through his Loader. Gumdramon shivers and hides behind Tagiru at hearing Shoutmon's name as he explains to Tagiru that it is none other than the Digimon King himself.
