Level Upper

Level Upper (幻想御手 (レベルアッパー) ) is a term used to refer to an audio file that is used by ability users of Academy City to gain abilities or enhance current ones. It is the focus of the Level Upper Arc a series of correlated events that occurred during the summer vacation period of Academy City which involved ability users using the Level Upper.

Etymology
The name "Level Upper" comes from the video game term level up, where a video game character gains a level and becomes stronger.

Principles
Using the Level Upper alters the brainwaves of the espers, through the stimulation of all five senses using synesthesia, to the pattern to that of Kiyama Harumi. This is due to the fact that she wants to create a brainwave network, that she will use for its calculating abilities, using the AIM diffusion fields of the espers as a common protocol in order for each brain to connect and become a network. Due to her being the one with the one whose brainwave patterns are being mimicked, she becomes the administrator of the network, which allows her to use all powers of the espers in the network. It is presumed that she uses the calculating abilities of the espers in the network, the same way Accelerator uses the calculation abilities of the Misaka Network, directly using their brains.

Those who use the Level Upper connect to the Level Upper Network, they gain powers not because of the fact that they have used the Level Upper, but because other espers are present in the network. This allows the esper to temporarily raise their level. Those who have the same powers, share the same experiences, allowing them to use their powers more efficiently.

Side-effects
Using the Level Upper causes the user to be put in a comatose state, as apparently, all those who are part of the network lose control of it. Also, the one controlling the network is also capable of accessing all the abilities of the users who are connected to the network.

Finally, when the controller of the network loses control of it, the consciousness of its users will form an entity made out of their AIM diffusions on the spot where the network lost control, this phenomenon is called an AIM Burst. The AIM Burst also causes painful convulsions to the unconscious users when it occurs, it is described as being tormented by a terrible dream and can only be cured by using the Level Upper treatment program.

Background
The creator of the Level Upper is Kiyama Harumi, an AIM researcher and previously among those in charge of teaching Child Errors as a part of the experiment she was participating in. As the experiment went on, she grew close to the students that she taught. During the experiment, the esper abilities of the Child Errors were purposely overloaded (as planned by Kihara Gensei), and as a result, the children were injured and put into comatose states. Harumi was horrified by what had happened to her students, which caused her to quit her job at the institute she was working at. She became determined to find a way to cure the children and wake them up from their slumber.

Creation and Conception
Harumi still determined to help the children requested 12 times for the use of Tree Diagram to perform a calculation but is denied permission every time, however she discovers the incredible computational powers of that the Misaka Network provided due to the 20,000 minds of the Misaka clones and opts to create her own. After researching material on synesthesia, as well as using the knowledge on how to tune brainwaves from Kihara Gensei, she creates a sound file to stimulate the brain and alter its brainwaves, she also creates a treatment program for it. It is unknown how she distributed the file, though the file can be obtained by either buying it from sellers or accessing it from internet sites.

Users
Kiyama Harumi estimated the number of Level Upper users to have been around 10,000, which to her was a sufficient enough replacement for the Tree Diagram.

The list of notable users below are listed in alphabetical order.
 * Akemi
 * Elder Sister
 * Jufuku Miho
 * Junta (Railgun anime)
 * Junta (Railgun manga)
 * Kaitabi Hatsuya
 * Koujun Kikuhiko
 * Kushiro Katabira
 * Mako
 * Morimoto Futari
 * Muu
 * Okahara Ryouta (anime only)
 * Oomura Jirou
 * Saten Ruiko
 * Trick

Trivia

 * Level Upper is a soundtrack found in the 2nd Toaru Kagaku no Railgun Original Soundtrack, and can be heard in ​​​​​episode 7 of Toaru Kagaku no Railgun.