Group

GROUP is a large underground organization composed of several main field operatives and is controlled by Academy City. The faction is also specifically refers to its four field operatives: Tsuchimikado Motoharu, Accelerator, Unabara Mitsuki, and Musujime Awaki. And is referred to as "a small group that exists in the underworld, working to defend the mainstream society."

Referenced during the invasion of Academy City where Accelerator becomes its newest recruit. They are later properly introduced during the Skill-Out uprising to deal with Komaba Ritoku's troublesome plans against the city.

Profile
GROUP was formed to take care of internal affairs of Academy City's dark Side, similar to ITEM, and more often than not, perform illegal acts for Academy City. Like other organisations such as ITEM, GROUP take orders from a person who only contacts them via telephone, though Accelerator seems to be contacted by their backer more often than the others. After the events of Volume 15, GROUP remains the only underground organisation that remains intact out of the five that were introduced in the same novel.

After the events of Volume 19, Accelerator leaves GROUP in order to help an ailing Last Order.

After the war, the members of GROUP are freed of the dark side's grasp. If they will ever officially reunite as GROUP again remains to be seen.

Organization
There are four core members of the organization who do the field work during missions. They are composed of powerful Espers and Magicians and were all blackmailed in some way to join in order to protect something important to them.

Field operatives

 * Tsuchimikado Motoharu
 * Accelerator
 * Musujime Awaki
 * Etzali under the guise of Unabara Mitsuki

Other members
There are other members of the organization, such as the technical department which supports the organization by giving the members useful technical aid. There is also a group that cleans up and disposes evidence after missions.

The organization is also composed of telepath-type espers and Powered Suit operatives.

Background
GROUP members apparently are recommended to stay in the building known as the "Nap Room." It isn't required for members of GROUP to sleep there.

Skill-Out Uprising
Due to Academy City currently fortifying its anti-Roman Catholic battle lines, the defense on the inside has gotten thinner. GROUP was given a job to do a clean sweep of a force that is going to use that gap in the defences to do some damage to the functionality of Academy City.

Battle Royale Arc
Tsuchimikado met Management inside his closet disguised office inside a department store, he posed as a client to gain entry and catch him. Meanwhile, Accelerator asked the electrode designs from Heaven Canceller at gunpoint, to which the latter complied. Tsuchimikado then had Etzali search Management's apartment for information on contacts and business deals. While Unabara was doing the investigation, the apartment was raided by a group of black-clad men apparently destroying the information that GROUP is after. In the aftermath of BLOCK raiding the apartment worried about Management's information getting obtained by another dark side organization, Tsuchimikado then showed that he was aware of Etzali's true identity and power and realized that in the confusion he had infiltrated BLOCK when they found Yamate's corpse and give an explanation to Accelerator and Musujime. After using a reader to scan the chips that Etzli found in the apartment, they found out that he was used to hire Sunazara Chimitsu and realized that the target was Oyafune Monaka. While searching for Chimitsu, Tsuchimikado and Accelerator saw Last Order asking Uiharu for help looking for Accelerator, much to his annoyance and Tsuchimikado's amusement until he spotted Maika in the crowd as well. Suddenly the Wind Defense nearby turned off they realized that it had been done with Chimitsu's Magnetic Sniper Riffle. After the failed attack thanks to Accelerator they found the hotel room that Chimitsu had fired from already abandoned when Accelerator informs him by phone that his employer is a rival group SCHOOL.

Later they discover that other organizations existed similar to theirs and were in motion and wonder which ones were involved with the destruction of Management's apartment, the attack on the paddy wagon, which one Etzali was concealing himself a part of and why did SCHOOL try to assassinate Oyafune Monaka. Shortly thereafter they received information that District 5’s Virus Isolation Center was being hacked while Accelerator protest at being sent to deal with this, Tsuchimikado states that the culprits are most likely one of the other groups and that they have betrayed Academy City and began to move. While heading to District 7, they received information that a satellite control center is under electronic attack and then concluded that some other group is trying to split them up and used the Virus Isolation Center as a decoy. Accelerator then decides to head to District 23 despite Tsuchimikado's protests and goes in order to prevent Hikoboshi II from being used as a weapon. He then contacted Anti-Skill to ask information about the sattelite but the "man on the phone" who usually gives instructions to GROUP interrupted so Accelerator asked him instead. After the conversation with the "man on the phone," his phone began ringing again, and this time, it was Unabara who just informed him that SCHOOL is not the one who is hacking the satellite but BLOCK, the group where he disguises. It turns out that the satellite will be used to attack District 13.

On the way, Accelerator met someone from yet another group called MEMBER and they fought. Tsuchimikado and Musujime later meet back up with both Accelerator and Etzali after the latter ruined BLOCK's attempt to bring 5000 mercenaries into Academy City. They then argued about the actions of SCHOOL and BLOCK before interrogating one of BLOCK's mercenaries that they captured about their plans whom they learned that their target was the Juvenile Hall in District 10 to take Musujime's comrades as bragging chips to gain entry to the windowless building and then assassinate Aleister Crowley. After their arrival to their destination, they split up again where Etzali stays to fight Xochitl, Accelerator goes to finish off the remaining mercenaries while he and Musujime go off to where her comrades were being held. They the meet the leader of BLOCK Saku Tatsuhiko who then has argument with his second Teshio Megumi on how they would use the hostages ending with Tenshio knocking out Saku. Tsuchimikado tries to fight her but is easily overpowered by her experience and own version of Anti-Skill subduing technique. After the fight he asks Musujime if she was alright before they both rejoined the rest of GROUP upstairs.

Accelerator then fought with Kakine Teitoku and defeated him. Tsuchimikado who is hiding among the crowd of onlookers recovered the Tweezers. He then shares the purpose of the device and the existence of UNDER_LINE. They decoded data and found information on several things relating to the Battle Royale including the existence of DRAGON.