Toaru Kagaku no Railgun S Episode 12

Tree Diagram (樹形図の設計者(ツリーダイアグラム）)is the twelvth episode of the second season of the Toaru Kagaku no Railgun anime series, and the 36th episode of the series overall. It was first aired on June 28th, 2013.

She had discovered that her enemy was Academy City itself. The Level 6 Shift Project, the "Experiment", held in the noisome depths of the "darkness" that Mikoto is obsessively fighting had struck her down with a sense of helplessness.

However, she herself must put an end to it. Finally, Mikoto sets forth towards a new target, the Tree Diagram, a supercomputer whom the best minds of Academy City seek out, and the very computer that suggested the plan in the first place.

Meanwhile, Touma once again meets Biribiri's little sister, hesitating before an abandoned cat, and is later involved in taking care of it

Major events

 * MISAKA 10031, 10032 learn about/experience the following emotions which are from then on permanently stored in the radio noise network: happiness, anger, frustration, irony, bewilderment, and sadness.
 * The 10031st Level 6 Shift experiment begins.
 * Mikoto discovers that Tree Diagram has already been destroyed.

Adapted From

 * Toaru Kagaku no Railgun Manga Chapter 032
 * Toaru Kagaku no Railgun Manga Chapter 033
 * Toaru Majutsu no Index Light Novel Volume 03

Characters

 * Misaka Mikoto
 * Uiharu Kazari (not appearing)
 * Saten Ruiko (not appearing)
 * Haruue Erii (not appearing)
 * Shirai Kuroko
 * Kamijou Touma
 * Misaka 10031
 * Kusakabe Yumi
 * Amami Eika
 * Misaka 10032
 * Misaka 10032's cat (also called Dog)
 * Accelerator
 * Index (mentioned by Touma)
 * Misaka 9982 (flashback)

New Characters

 * Misaka Misuzu (flashback)
 * Himegami Aisa (mentioned by Touma)

Locations

 * Academy City
 * School District 7
 * Tokiwadai Dormitory
 * School District 23
 * Book-On

New locations

 * Tree Diagram Information Receival Center

Abilities

 * Electromaster (Railgun and Variant) - Misaka Mikoto, Level 5
 * Accelerator (ability) - Accelerator, Level 5

Trivia

 * Grow Slowly returns as the ending theme, replacing stand still from the previous episode.
 * Misaka 10032 identifies herself as such only after seeing both Misaka 10031 and Accelerator together for the experiment. Here, the Misaka 10031–10032 confusion is finally cleared during this episode as Misaka 10032 meets up with Misaka 10031, a fact that is only slightly shown in the manga and revelead in an omake of the 6th Toaru Kagaku no Railgun Manga Volume.
 * Touma references both Index and Himegami Aisa in her conversation with Misaka 10032 regarding taking care of cats, specifically Sphynx.
 * The Destruction of Tree Diagram and Remnant is referenced during this episode.
 * The anime makes it clear that Mikoto was planning to stop the Level 6 Shift experiment by having Tree Diagram explain that the fight between her and Accelerator permanently prevented Accelerator from becoming a level 6 esper. She then planned to destroy Tree Diagram.

Referbacks

 * Touma references his meeting with Misaka 10032 with the beverages last episode to Mikoto.
 * The cat that appears in this episode is the same cat that appeared back with Misaka 9982 in episode 05.
 * Misaka 10031 references Misaka Mikoto's rejection of her from the previous episode.
 * Misaka 10032 references animals' fright of Mikoto and her clones because of their electricity from episode 05.

Cultural References

 * Tokugawa Ieyasu is referenced by Misaka 10032 during this episode. He was the founder of the Tokugawa shogunate which ruled over Japan for more than 200 years.
 * Erwin Schrödinger is referenced as well by Misaka 10032, as a name for her cat. The reference here is different from episode 10 of Toaru Majutsu no Index as Touma simply states that it is taboo to name cats after him. Here, Touma references the entire thought experiment.

Animation Trivia

 * Animation from episodes 5 and 6 are reused as flashbacks for this episode. Moreover, as well as from the previous episode during Misaka 10031's recollection of Mikoto yelling at her.

Unanswered Questions

 * Who was the nun and shrine maiden Touma talks about to Misaka 10032?
 * Did Accelerator just save the person that was getting beat up by the thugs?
 * How was the Tree Diagram destroyed?
 * When Accelerator stated that there were dolls who could carry out their missions with silence, was he stating this out of a form of praise of the MISAKA clones?
 * Where was Mikoto's father in the flashback?
 * What will Academy City do now that it's "brains" have been destroyed?
 * What will Mikoto say to Kuroko when she goes back to the dormitory?
 * What exactly is the joint operation that MISAKA 10032 is performing with MISAKA 10031?