Mutsumi was the black-winged experiment hybrid made when the scientists were screwing around with Iceman/Witsarunemitea DNA. She's the origin of all the winged people, and was reincarnated within Kamyu.

Witsarunemitea is the monster god that Hakuoro was half of, the Iceman part. The monster part is the true form of the god Witsarunemitea, and was sealed/split by Mutsumi after he rampaged the first time and turned all the humans to goop.

Yamato was founded by stealing the science results and then replicating them ('decoys', fake masks, etc.). Tsukuru is about where the original lab was, and all its animal people descend from those experiments cloned from Iceman's DNA. They made several thousand, who scattered all over the regions seen in the first series (Tsukuru, Na-Tunku, Kunnekamun, with the Onkamiyamukai overseeing them all as diplomats).