Digimon Tamers

A mysterious girl arrives with a Digimon Dobermon. They were sent by Azulongmon to make the Tamers able to Biomerge to Mega level. They came to know that Dobermon is a gift and he sacrifices him to make them Biomerge digivolve. They were told that the major part of D-Reaper is in the real world and it's up to them to stop this.