Lady Koriko was a cold and proud anthropomorphic cat of the Geishu Clan.
Lady Koriko was married to Nagao. However, Nagao was disillusioned by the rigid structures of samurai society. Lady Koriko was cold and emotionless and obsessed with honour and her place in society. As a result, Nagao abandoned his wife and child When he died, Lady Koriko hired Miyamoto Usagi to retrieve his daisho for her, so that it might be passed on to her son. She was not interested in regaining the body of her husband.