Mikagami Nagisa's Clique

Mikagami Nagisa's Clique (水鏡凪紗の派閥), also referred to as the Mikagami Clique (水鏡派閥), was the second largest clique in Tokiwadai Middle, one year prior to the main story, led by Mikagami Nagisa.

Principles
The Mikagami Clique was the second-largest of Tokiwadai's 'big three' cliques (behind the Sha Clique and ahead of the Hasekura Clique), one year before the main story, during Misaka Mikoto and Shokuhou Misaki's first year at Tokiwadai Middle. It was led by third year student Mikagami Nagisa, whose Oil Direction ability allowed her to manipulate oil, including the fats in the human body, with no number two position. Around 19% of Tokiwadai's students were members of the clique. According to Shokuhou Misaki's analysis, ignoring numbers and in terms of power, the clique was the second most powerful of the three, behind the Hasekura Clique.

According to Kessai Kiyoshi (a first-year member of the Hasekura Clique but actually related to Sha Danshan), of the big three cliques, it was said to be working the hardest to get results, apparently made up of students who were mostly drawn to her oil control ability and sought her to fulfill their own desires (such as manipulating fat in their body to enhance their bust or slim them down), with Mikagami only doing this for those who contributed the most to her clique.

Background
In her years before middle school, Mikagami Nagisa was continually approached by people who sought help from her ability, to the extent that most of her free time was taken up by it. In an effort to change this, when she entered Tokiwadai, she formed a clique and made it a rule that she would only use her ability for others as a reward, in an effort to minimize people approaching her. However, Mikagami underestimated how many people cared about their appearance and were willing to join, as well as the effort they would put in to get results, to the extent that the Mikagami Clique overtook the Hasekura Clique to briefly become Tokiwadai's number one clique before being overtaken by the Sha Clique.

First Year Arc
During the summer, after the clique leaders' initial encounter with Misaka Mikoto in May, the Mikagami Clique was involved in a conflict with the Hasekura Clique, secretly engineered by Sha Danshan to undermine her rivals' progress while Hasekura Reiri was away for a demonstration in Paris. After the initial attack on Kazan'in Tsukasa, supposedly by the ability of Enjou Kasumi whom she quarreled with earlier in the day, the Mikagami Clique angrily confronted the Hasekura Clique who denied the allegations. A further attack that injured another Mikagami Clique member led to the nearby Kessai being targeted for retaliation, though it was stopped by Misaka Mikoto and Shin'enkouji Rurikakesu.

While others in the clique were in favor of striking back, an internally-dismayed Mikagami rejected it, though she was dissuaded from trying to resolve things by apologizing. While she was walking with Sukezawa Sena and Kadosaka Rina, they were ambushed by Yasutoba Suika, who had ignored Hasekura's orders not to do anything until she returned, intending to take out Mikagami herself. After an initial escape and Mikagami venting her frustrations, Sukezawa and Kadosaka decided to face Yasutoba themselves to make up for the stress they'd put their leader under. They were defeated but refused to call their leader over, however Mikagami returned before they were harmed further and managed to defeat Yasutoba, despite her opponent's attempts to rattle her through comments about her clique members only wanting her for her power.

After this ambush, tensions remained high, with certain members of the Mikagami Clique in favor of a counterattack against the Hasekura Clique. Walking home at night after voicing such thoughts at a meeting, Urui Aika spotted Misaka Mikoto practicing her new technique and on trying to leave, accidentally ran into a group from the Hasekura Clique. A clash of esper abilities resulted, with Mikoto intervening on the outnumbered Urui's behalf. When this initially secret help was exposed, Amano Ayane challenged Mikoto to test her power, leading to her Railgun being used in action for the first time to save the Hasekura girls from a severed wind turbine blade. Urui thanked Mikoto afterwards, though she noted that others in the clique might be upset about the interference.

After Hasekura returned and began her own investigation into the conflict, Mikagami agreed to her offer of a temporary truce in light of a potential external culprit. Most of her clique voiced objections, but Mikagami quelled them by promising to use her ability for every one of them if the culprit was caught and the conflict ended. When Hasekura tried to provoke the mastermind into action by making it appear as though Shokuhou was aiding her, members of the Mikagami clique discussed the rumors, believing the ruse.

When the Hasekura Clique confronted Montgolfier, the company suspected of being behind the attack, the Mikagami Clique provided reinforcements along with the Sha Clique after a battle broke out, though Mikagami had previously been reluctant to put her girls in danger.

As she had promised, Mikagami gave everyone in her clique beauty treatments after the conflict was resolved, though by October a number of them were regretting their choices. Around this time, some members of the clique went to see a performance of commedia dell'arte at a theatre in District 9, as part of their art appreciation elective, along with members of the Hasekura Clique (with things still somewhat on edge between them despite the conflict's conclusion) and Shokuhou Misaki. During the performance, a fire broke out backstage, which the Tokiwadai students only learned about on their way out. Although briefly overwhelmed by the panicking crowd, crowd control and prompting from Shokuhou led the students to all work together in ensuring that everyone got out safely.

Not long afterwards, having fulfilled her pledge to her girls, Mikagami kept her promise and disbanded her clique.

Named s

 * Mikagami Nagisa (Leader)
 * Urui Aika
 * Kazan'in Tsukasa
 * Asakura Olivia Moa
 * Kadosaka Rina
 * Sukezawa Sena

Trivia

 * Similar to the other two cliques in the 'big three', all members of the Mikagami clique seen so far as of have light-colored hair, depicted with white in the monochrome sections of the manga, like with their leader (blonde in her case).
 * Kazan'in Tsukasa and her unnamed friend had darker shades of hair in the initial magazine release of Chapter 133, but this was changed in the tankobon version and future magazine releases afterwards. Sukezawa Sena also had a darker shade in the magazine release of Chapter 132, but this was changed by Chapter 134 and similarly changed in the tankobon version of Chapter 132.
 * With the exception of Kazan'in Tsukasa (who uses compressed air), the majority of the known abilities among the clique's members, at the time of Chapter 143's release, involve the manipulation of, including oil, natural rubber, keratin, chitin, and calcium.