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.
This episode takes place in Soul Society 110 years ago. Most of the Captains have gathered to celebrate the promotion of the 12th Squad Captain to the Royal Guard, known as Zero Squad. Meanwhile, Yoruichi (currently the Captain of Second Squad) has recommended her Third Officer, Urahara Kisuke for the now vacant position. However, Soi Fon is not happy about this and follows Urahara in an attempt to prove he is unworthy of the position. Yoruichi hears of this and mistakenly thinks that Soi Fon has a crush on Urahara. Because of this Yoruichi arranges for her to attend the Captain's Qualification Exam to watch him in action. Although Urahara, is delayed in getting to the exam because of having to capture a group of deserters he makes it in time and manages to pass. As such Urahara Kisuke is appointed as the new Captain of the 12th squad, although vice-captain Aizen Sousuke is less than pleased.
Urahara Kisuke has now become Captain of 12th squad but his new Vice-Captain Hiyori Sarugaki refuses to accept him. He even goes so far as to let her win in a duel against him to try and gain her confidence. However, after a pep talk from Shinji he decides to just be himself and stop worrying about it.
Urahara and Hiyori head to the Maggot's Nest prison, which houses former members of the 13 Protection Squad's deemed dangerous to Soul Society. Once they arrive Urahara goes to see the most dangerous inmate, Kurotsuchi Mayuri. He asks Mayuri to join his new organization the Technological Research Bureau as his Lieutenant. Meanwhile, Byakuya meets with his grandfather and Yoruichi whilst Ukitake tries to persuade Shiba Kaien to become his vice-captain. Also Aizen meets Ichimaru Gin for the first time.
This episode is set nine years after the previous one. The 9th squad are sent to investigate after people begin to vanish from Rukongai. Whilst out on patrol Captain Kensei Mugurumathey saves a young boy from a hollow, his name is Shuhei Hisagi. He then discovers that 10 of his own men have also vanished and calls for the Technological Research Bureau to help in the investigation. As such Hiyori is dispatched.
An emergency is declared following the attack on the 9th Squad. Captains Shinji Hirako, Love Aikawa and Roujuurou Ootoribashi are dispatched to investigate along with vice-captain Lisa Yadomaru and Hachigen Ushoda from the Kidou Corps. When they arrive they discover Hiyori fighting with a 'hollowfied' Kensei and soon a 'hollowfied' Mashiro also appears. Meanwhile, Urahara and Tessai Tsukabishi (Captain of the Kidou Corps) disregard their orders and also head out to investigate.
Shinji's group manages to restrain Kensei using a powerful Kidou spell but then Hiyori also undergoes 'hollowfication'. They are then attacked by Tousen and as the rest of the group undergo 'hollowfication' Shinji battles against Aizen and is almost killed when Urahara and Tsukabishi arrive to save him.
Urahara confronts Aizen about his hollowfication research but ultimately Tsukabishi is unable to capture him. Meanwhile, after being transported back to the 12th Squad headquarters Urahara decides to use Hougyoku to save Shinji and the others. Urahara and Tsukabishi are then arrested by Central 46 and blamed for the hollowfication experiments. However, before their sentences can be carried out Yoruichi appears and helps them escape to the real world.