Whether you're Keros' Champion or not, you are to all floofs an ignorant barbarian who barely knows anything about their culture, including the fact that it's matriarchal and thus it's
Kiyoko's job to work out a marriage for Kinu, not yours. The fact that you don't know the first thing about kitsune politics (and because of the situation, Kinu is basically a political grenade that needs very careful handling) makes you completely unsuited to make any decisions here, as far as they're all concerned. It's not like this is a big mystery,
Tobs has talked about it before and the key details are in the game for everyone to see.
Japanese myths include the life-stealing as well, they're called kitsune rather than kumiho, literally every named floof has a Japanese name and Tobs has gone into the inspirations for his work
in detail and kitsune history and culture are very much Japanese-inspired, with special emphasis on the Heian Period.