It is a story set in the near future, when the existence of "Digital Monster" is confirmed because of the discovery of a Net world, the "Digital World". Daimon Masaru is a rowdy 2nd year junior high school student who spends all of his time fighting and utterly fails at computers. His father, Suguru, is a professor and scientist who was the No.1 leading authority on researching the Digital World and has been missing for ten years. The government establishes a private national organization, "Digital Accident Tactics Squad" or DATS, to especially handle the virulent Digimon. One day, Masaru meets an escaped Agumon that DATS has labeled as "Substandard" and was to dispose of. They become friends after a fight, and DATS recruits Masaru. Together with their DATS teammates, Thoma H. Norstein and Gaomon and Fujieda Yoshino and Lalamon, Masaru and Agumon go on to resolve various incidents that Digimon causes and protect the human world from the virulent Digimon.