Ep 2. Connected Hearts! The Left Fist of Certain Death

Having sustained severe injuries in battle, Rukia escapes to the World of the Living and is saved by Ichigo. A mysterious woman then arrives through the Senkaimon and proceeds to attack the two using the same Zanpakuto as Rukia. Rukia tells a confused Ichigo that the woman is in fact the manifested form of her Zanpakuto, Sodenoshirayuki, and that the other Zanpakuto have also gone rogue to cause destruction in the Seireitei.