Kiefer is a Bumon of a different nature, he doesn't care much for the rough day to day lifestyle that he was born into,
so long story short he left to find a place more in tune with his, "unique living style."eventually after traveling for a while he came across the Toki in the tropical underground.
Lots of things happened but ultimately the important part is he stayed with them and they welcomed him with open arms, yay happy endings :D