It seems to be based on genetic compatibility, which would make sense if it stayed within families. In canon Suna, it's had three hosts. Presumably, the first host (http://naruto.wikia.com/wiki/Bunpuku) back when the villages were first founded... who likely survived to see the 2nd Kazekage's reign (in which he was the first to research tailed beasts)<br/><br/>In this game, Chikamatsu Monzaemon (Chiyo's teacher) captured the Shukaku in a tea kettle, which was then transferred to Bunpuku. The 2nd Kazekage (http://naruto.wikia.com/wiki/Second_Kazekage) being the father of the 3rd Kazekage (http://naruto.wikia.com/wiki/Third_Kazekage) and Aimi, had Chiyo transfer the one-tails from the old man to his own daughter, Aimi. The 3rd Kazekage (Isamu) developed the Satetsu in an effort to bond with her.<br/><br/>Presumably, if the PCs don't change anything in the timeline- the one-tails will either be resealed into a tea kettle and later transferred to Gaara... or transferred into Gaara directly. In either case, resulting in her death. :o Aimi may or may not have some genetic relation to Yashamaru and Karura...<br/><br/>Also, seems like Myst is away from E for awhile- and I'm taking this game slow. I haven't forgotten about it, though. Of course not. :P<br/><br/>I do have to warn you guys though that I'll be going to the field again for at least 30 days on April 23rd.