Haineko is the manifested spirit of Rangiku Matsumoto's Zanpakutō that is seen during the Zanpakutō Unknown Tales arc.
Haineko's spirit takes the form of a werecat. While looking mostly humanoid, she possesses a tail, cat ears and pink fur over her body. Her most distinctive features are her large hips and rear, in contrast to Rangiku Matsumoto's large breasts. She is highly mischievous and tends to get bored rather easily. She also seems to enjoy making fun of Matsumoto.