Board Thread:WARNING ALL USERS False Info\Spoilers/@comment-59.178.181.142-20140306185455/@comment-24178824-20150619001550

As for why Ms. Yukimura has a seemingly inconsistent age my take on it is this.

At 900 Kitsune gain their ninth and final tail, maybe that's when they actually become an adult. Maybe thats why they're known as being mischievous and tricksters, because for century's they're children/teen-agers, maybe that's why a nine tailed Kitsune is supposed to be very wise. Because they're mature, at 900 Ms. Yukimura finally became a fully grown adult Kitsune.

So maybe it's just their natural life cycle, a very long growth period followed by rapid maturity.