Toaru Majutsu no Index Wiki

A large satellite dish of Tree Diagram Information Receival Center

The Tree Diagram Information Receival Center (樹形図の設計者ツリーダイアグラム情報送受信センター?) is a facility found in School District 23 which, as the name indicates, received data from the supercomputer Tree Diagram prior to its destruction.[1]


A large satellite dish is located in the facility as the Tree Diagram is located in space on the Orihime-1 satellite. The facility uses sensors as well as Security robots. Most likely before falling into disuse, the facility may have been more heavily guarded.


Mikoto in the control room.

Not only does it receive information but it exchanges data with the Tree Diagram, both for sending to requests and receiving responses. Moreover, the facility also exchanges data with other satellites.[1]

According to Misaka Mikoto, it is the only window to communicating with Tree Diagram at specific times. The facility can handle hundreds of transmissions between the satellite and the facility a day.[1]


Toaru Kagaku no Railgun

Sisters Arc

Main article: Sisters Arc

In a last ditch effort to stop the Level 6 Shift project, Mikoto goes to the facility in order for her to hack the Tree Diagram, the same supercomputer that dictates the movements of the researchers doing the experiment in the first place. By the time Mikoto arrived, there is still minimum security and the machinery is still being run despite being abandoned by personnel for quite a long time since the Tree Diagram's destruction.[1]