Byakuya, Disappearing With the Cherry Blossoms
Ichigo finds Rukia injured in the world of the living, and that she is being attacked by a strange woman, who uses rukia's abilties. It is revealed to be that this woman is Rukia's Zapakuto, Sode no Shirayuki. Ichigo successfully forces the renegade zapakuto into submission, and Sode no Shirayuki retreats back to soul society. Ichigo brings Rukia to the Urahara shop, where she reveals that the Shinigami's zanpakuto's have attacked their masters, and reveals that Byakuya was seemingly defeated fighting by his own zanpakuto, Senbonzakura. The remaining shinigami of the gotei 13 squads regroup to the 4th Division headquarters while they try to re-establish their defenses, and learn more about the zanpakuto rebellion. and Urahara observes that only the Zapakuto in Soul Soceity are affected and that those in the real world are unaffected, and decides to try to capture one of the materialized zanpakuto in an attempt to learn more about their new enemy. In the middle of the night, Rukia leaves for Soul Society, apparently in search of Byakuya. Ichigo and Yoruichi leave for soul society in an attempt to go after Rukia and save soul society.
Aired 04/08/2009EP 231 - Byakuya, Disappearing With the Cherry Blossoms

Bleach
Ichigo Kurosaki is a rather normal high school student apart from the fact he has the ability to see ghosts. This ability never impacted his life in a major way until the day he encounters the Shinigami Kuchiki Rukia, who saves him and his family's lives from a Hollow, a corrupt spirit that devours human souls.
Wounded during the fight against the Hollow, Rukia chooses the only option available to defeat the monster and passes her Shinigami powers to Ichigo. Now forced to act as a substitute until Rukia recovers, Ichigo hunts down the Hollows that plague his town.