Months after the events of the TV series, Takato Matsuda, Ruki Makino, and Jianliang Li are planning a surprise birthday party for Ruki when a train-shaped Digimon called Locomon barrels into the real world. With their partners Guilmon, Renamon, and Terriermon, the Tamers have to catch Locomon and stop it before it reaches the portal back to the Digital World, birthday plans on hold. This movie is a direct follow-up to the Digimon Tamers TV series and the second Tamers film after Battle of Adventurers.