Digimon Data Squad (2006)

A 16-year-old boy, Marcus Daimon, an undefeated street fighter, meets Agumon, who has escaped from the Digital Accident Tactics Squad (DATS), a secret government organization set up to defend the human world from invading wild Digimon. After fighting each other, the two quickly become friends, and through a series of events, are inducted into DATS, where they hope to grow in strength.