What's this Kamiya/Yagami stuff?
 

Okay, so I think it was some time after the first season ended that there was a revelation about Tai and Kari's last name actually being Yagami. Now I was under the impression that we didn't dub any of the DigiDestined's last names, and the first episode made clear that even their first names were just "American" nicknames.

Could somebody please explain this?