Kuyama Kihan

Kuyama Kihan (工山規範) is a minor character introduced in Toaru Majutsu no Index. A criminal hacker, he tries to hack into a system defended by the Goalkeeper, but is cornered and apprehended.

Personality
Being a hacker, Kihan always apparently tries to improve himself, wanting to "perfect his master key", a metaphor for his skill to hack into systems. He has shown distaste for casual computer users. He also notes to himself that one of his flaws is that he was a bit distracted while "on the attack".

Background
Kihan is described in the narrative as the kind of hacker who doesn't really care about the distinction between hacker and cracker, and describes him more of an internet criminal. He apparently first touched a computer in the lower grades of elementary school and after randomly hitting a few keys he unlocked the password for the faculty. From then on Kihan had an interest in the holes in systems, and by the time he was in high school he had an odd criminal record. Despite this, he has never used his skills for profit.

A week prior to the Second Friday of June, several hackers that Kihan knew had been arrested after each one of them tried to hack into a system that the Goalkeeper had defended. Wanting to better himself in hacking and surpass the Goalkeeper, he seeks to challenge her.

The Second Friday of June
Setting out with his scheme to challenge the Goalkeeper, Kihan goes to an open café with a wireless LAN spot, knowing that it would be too dangerous to do the operation in his home. Using his customized notebook computer that lessens the danger of him being tracked by Academy City when accessing an unauthorized terminal. Despite his preparations however he is nervous in facing the legendary Goalkeeper, but he is determined to "perfect his master key" as he puts it. As he prepares his shortcuts to various commands and programs for hacking, he notices someone asking if the open café has an LAN. She apparently wants to send the report she had just written without going to school to submit it. Seeing this, Kihan refers to Yomikawa Aiho as an amateur as she should've noticed the sign on the café's door that it had LAN, and that she shouldn't even be sending her report on an unknown wireless LAN as it could be picked up by anyone without the proper countermeasures.

After silently expressing his contempt for all the casual users who loved computers but didn’t know anything about them, Kihan begins his work. He brings up the processes that were usually dealt with in the background up to the surface, and finds the system that the Goalkeeper manages. He manages to slip into the system through the point of contact between Anti-Skill and Judgment to exchange information. He is however intercepted and is forwarded to another site. Kihan who has anticipated this, circumvents this. Seeing this, he knows it is the work of the Goalkeeper as it was used as weapon against hackers like him. As he enjoyed what was happening, he becomes distracted by a certain girl's voice. She, with her flowers in her hair, is sitting at the table across the woman, Aiho, from before. Kazari says that she finally found something and then says that she just managed to stabilize the speed, though she becomes worrisome again.

When he turned to his notebook computer again after being distracted, he finds several more traps prepared by the Goalkeeper, each one of them unique, and each one of them suited to take down a hacker like him. However, he was yet to fall for the traps and he manages to work his way deeper into the system. However, just when he thought he was going to win, a notification appears on his screen that says that his connection has been severed. This confuses Kihan as there should be no problem with the signal from the wireless LAN in the open café, and believes that the Goalkeeper's system must've lost power. Kihan wonders if he was noticed. He looks upon the notification, though determines that there is no sign that someone had gotten his information. He assumes that that someone has noticed him hacking and determined to cut the power. Just to be careful, Kihan uses a variety of "detours" so as to not leave behind any trace. Believing that he won in hacking skills on account that the Goalkeeper was forced to cut the power instead of continuing facing him, and that he could not be traced, Kihan shows no sign of worry on his face.

However, he notices something, since the Goalkeeper has severed the connection, it also means that same notification would also appear on the Goalkeeper's computer, meaning from there the Goalkeeper can check the date and time that the message was left on the system then he will be found right away. Kihan becomes nervous, and feels like the café’s security cameras and the lenses of the security robots on the road were aiming at him. Suddenly, a hand from an Anti-Skill grabs his shoulder, and tells him that he is in violation of the regulation against unlawful operation of electronic information. He has been caught. However, he is too preoccupied on how he was caught to be bothered by the Anti-Skill. He wonders how due to the timeframe that if the Goalkeeper was immediately able to determine where his signal came from, Anti-Skill couldn't have possibly got to him that quick. He wonders how his location have been discovered. At that moment, he sees the girl with the flowers on her hair, Uiharu Kazari, stands up and asks for a receipt from the cash register. Seeing her with the handheld device, Kihan realizes that it was made so it could use the wireless LAN, meaning that programs could be operated over the internet using it. Kihan refuses to believe that Kazari could have battled him with her handheld gaming device, but the pieces just fall into place as he recalls the first time he saw her yelling. Kihan tries to call out to Kazari and approach her, but is then thrown to the ground by the Anti-Skill. His calls however are not heard by Kazari, and she leaves without him getting the proof that she could have been the Goalkeeper. As he is handcuffed, he is impressed by the shadow of the Goalkeeper he managed to glimpse for a brief moment, and notes that the Goalkeeper is a "true hacker".

Quote

 * (From Index SS2): "But my master key has to be perfect. If there’s even one door it can’t open, a master key is nothing but trash."
 * (About Uiharu Kazari): "That’s a true hacker."