The A new Fox in Town Ending is an Ending in Prisoners of the Elder One. It occurs after using the Transfigurative Orb on Yuki.
The spell backfires, turning Erik into a kitsune. Yuki decides to give Erik a new name, Kuzunoha, and takes her as an apprentice, though Yuki eventually outlives her usefulness in Kuzunoha's eyes, and so is promptly turned into a slave.