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

 * The 10031th Level 6 Shift experiment takes place.
 * 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
 * Accelerator

New Characters

 * Misaka Misuzu

Locations

 * Academy City
 * School District 7
 * Tokiwadai Dormitory
 * School District 23

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.
 * 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.