After becoming a Kitsune and equipping the Fox Jewel you learn Kitsunetsuki, but contrary to the description listed on the item, you do not need to have the fox jewel equipped in order to use or equip Kitsunetsuki. Instead once you learn the technique, it seems to function as any other learned ability.
I am unsure if this is intended behavior and the description just hasn't been updated yet, but I'm posting it just to be safe.
I am unsure if this is intended behavior and the description just hasn't been updated yet, but I'm posting it just to be safe.