The names seen from Doman characters before our journey there have two possible explanations:

1. They're adopted pseudonyms. Considering all the Domans we met before going to Othard were ninja, having a pseudonym makes perfect sense.

2. In Yugiri's case, she's an exile from Sui-no-Sato, so is unlikely to have a "real" surname.

The name generator spits out names proper for Raen and Doman Hyur as well.