When a kitsune take human form and marries a human, they often have children. When the offspring are human, they inherit abilities (special physical or supernatural qualities). These in turn are passed to their children.
The word choice makes me think that the offspring aren't always human. Is there a story to corroborate my suspicions?
or...
It there a Shinto Myth in which a kitsune-wife give birth to something other than a human?