The eleventh season of the Bleach anime series, released on DVD as the The Past Arc, is directed by Noriyuki Abe and produced by TV Tokyo, Dentsu, and Studio Pierrot. The seven episode season is based on Tite Kubo's Bleach manga series. The episodes' plot follows the flashback arc of the series' storyline which retells the Visored's past.
The season first aired from February 10, 2009 until March 24, 2009 on TV Tokyo in Japan. The English adaptation of the anime is licensed by Viz Media, which has announced that this season will start airing on May 28, 2011. Aniplex collected the season in a series of two DVD compilations. The first DVD volume was released on November 26, 2009 and the second on December 16, 2009.
The episodes use two pieces of theme music: one opening theme and one closing theme. The opening theme is "Velonica" by Aqua Timez while the ending theme is "Sky Chord" by Shion Tsuji.
In the Soul Society 110 years ago, the Thirteen Court Guard Squads are made up of unfamiliar faces. The captain of Squad Five is the masked Visored, Shinji Hirako who currently resides in the World of the Living.
Kisuke Urahara replaces the newly promoted Kirio Hikifune as captain of Squad Twelve. Hiyori Sarugaki, lieutenant of Squad Twelve, cannot hide her dissatisfaction with the new captain.
Kisuke takes Hiyori to the Special underground Confinement Unit inside the Squad Two barracks. Nicknamed the Maggot's Nest, this place imprisons enlisted Thirteen Court Guard Squad members whose beliefs or actions have been deemed dangerous.
Nine years have passed since Kisuke Urahara was appointed captain of Squad Twelve. Bizarre deaths start to occur in the Rukon District where people disappear, leaving only their clothes behind.
Kensei Muguruma's and Mashiro Kuna's Spiritual Pressure disappears. The Seireitei deems this a dire situation. Kisuke Urahara, who sent Hiyori to Squad Nine, volunteers to go to the scene of their disappearance.
At Squad Nine's camp, Shinji Hirako and the others run into Kensei Muguruma, who is donning a strange mask. Kensei starts to attack them, and he is too powerful to stop even with all of them combined.
Sosuke Aizen suddenly appears in front of Shinji Hirako and the others. He draws his sword on Shinji, who is agonized by his Hollow transformation and cannot move his body at will.