Digimon Tamers (2001)

Takato, Ruki, and Lee are young Digimon Tamers who unexpectedly find themselves partnered with real Digimon, in stark contrast to the fictional ones from their favorite card game. Each child holds unique opinions on the proper way to interact with their Digimon. However, as more Digimon start to surface across Japan, they are forced to set aside their disagreements and unite against the invading digital threats.