Shirai Kuroko/Chronology (Toaru Kagaku no Railgun)

* Anime
* Novel
* Manga
* Railgun
* Astral Buddy
* Imaginary Fest

This article covers Shirai Kuroko's chronological history in *Toaru Kagaku no Railgun*.

## Chronology

### Toaru Kagaku no Railgun

#### Level Upper Arc

*Main article: Level Upper Arc*
Kuroko is seen doing her duty as a member of Judgment detaining espers whose powers were enhanced by Level Upper. Due to injuries she sustained from fighting Level Upper users, she couldn't partake in rescuing Uiharu from Kiyama Harumi or help Mikoto fight the AIM Burst.

#### Big Spider Arc

*Main article: Big Spider Arc*
Kuroko aids Mikoto, Konori Mii, and Kurozuma Wataru in fighting and putting an end to the Skill-Out gang, Big Spider.

#### Poltergeist Arc

*Main article: Poltergeist Arc*
Kuroko is first seen in this arc with Mikoto and Saten helping Uiharu's new roommate move in. Later they go to a festival where a Poltergeist happens, and after observing Erii's odd behavior right before the incident and some investigation, she begins to suspect that Erii is the one responsible, which strains her relationship with Uiharu. When the head of MAR, Therestina Kihara Lifeline's true intention for Erii and Kiyama's students was discovered, she slapped Uiharu to snap her out of her emotional breakdown. Later, she and Kongou joined forces to stall the MAR powered suits, then came to Mikoto's aid against Therestina herself. At the lab, they are again confronted by Therestina, only this time she use Capacity Down to disable them, except for Saten as she was a level zero and thus unaffected by Capacity Down, and went ahead to disable it, an act that earned her Kuroko's respect.

#### Sisters Arc

*Main article: Sisters Arc*
Although showing rarely, she is the one who opens up the question to Mikoto on what would happen if she were to meet a clone of hers, to which Mikoto gives an answer that she will soon regret. Throughout the story arc, she becomes concerned as to what Mikoto is holding and laments on how Mikoto cannot trust her enough to tell. Kuroko is forced to lie to and deceive their dorm manager for Mikoto's sake as she begins her one-man mission to take down the Level 6 Shift Project.

Later, after Mikoto believes she has shut down the Level 6 Shift Project for good, Kuroko calls Uiharu and Saten to determine what they should do with the current situation with Mikoto. Saten concludes that since Mikoto goes out every night and comes home tired, it can only mean that there is a boy involved, much to Kuroko's disbelief. After an alarm goes off in Vending Machine 7116, she immediately concludes it is Mikoto and proceeds to go investigate alone. She later finds Mikoto with Kamijou Touma leading to the now classic scene of their meeting. Regardless of her horror of Mikoto meeting with Touma, she is relieved that she has returned to her old self.

This is however short-lived, as Mikoto later discovers that the Level 6 Shift Project persists. Kuroko sees through Mikoto's change of behavior and suspects that Touma might have something to do with it, but is then asked by Mikoto a hypothetical question on what Kuroko would do if Mikoto were to do something irreversible to Academy City, to which Kuroko says that she will do her duty even if it is her Onee-sama. Kuroko's words relieves Mikoto but it doesn't help Kuroko's worry. Finally, as Mikoto goes off to destroy Tree Diagram to stop the aforementioned project, Kuroko lies alone in Mikoto's bed worrying about her. She recalls on how Mikoto acts normally when referencing "that idiot" (Touma), and wishes for him to come and do something. Her wish is seemingly granted, leading to their second meeting in the Sisters Arc.

As the Level 6 Shift Project is ended by Touma and the Sisters, Kuroko tracks down Mikoto on a bridge, whom has just met Touma but is unable to give the cookies she baked for him. Kuroko is surprised by Mikoto's reaction after she hears Touma say her name for the first time, saying that it is an expression she has never seen on her before.

#### Silent Party Arc

*Main article: Silent Party Arc*
Kuroko plays a supporting role in the arc. As Mikoto returns back to normal after the events of the Sisters Arc, Kuroko welcomes her back with open arms. When Mikoto once again starts acting secretive, Kuroko is fine with it, believing that Mikoto will be back, and supporting in her endeavors. However, when she opens up to them that she needs their aid in helping Febrie from the dark side of Academy City, Kuroko jumps at the call to help her. She is the one who rescues Mikoto from the office building STUDY stuck her in after she was captured, using Uiharu as the one who tracks the nanodevice embedded inside Mikoto, and Saten as the lookout. She easily defeats the security robots stationed there.

Kuroko gets involved when the group decides to take on STUDY and the Silent Party without any help at all from Anti-Skill for the sake of Febrie and Janie, Febrie's sister. She stands as a sole guardian of one of the Academy City Research Exhibition Assembly venue entrances, and faces off against several of the 20,000 plus STUDY Powered Suits controlled by Diffusion Ghost. After being joined by other Judgment members rallied by Yanagisako Aomi, she is shocked after all of them copy her famous catchphrase. She then does battle against the Powered Suits, and uses the javelins from Tokiwadai, easily defeating a Powered Suit with a single hit. She also uses her ability to rescue Judgment members who are in trouble.

Kuroko is part of the little conference held after Mikoto defeats Aritomi Haruki, STUDY's leader, who has launched the AIM bomb. Here, she is the one who is to go with Mikoto and teleport her back after she has used the Ekaterina II S to destroy the AIM bomb. As they strap themselves in the mecha while waiting for launch, Mikoto apologizes to Kuroko for involving her, to which she replies that she doesn't mind for she is finally fighting side by side with Mikoto. With that, they are launched into space by Kongou's Aero Hand. Kuroko becomes visibly sick upon arriving in the upper atmosphere, but manages to teleport away as Mikoto begins to do her part. Kuroko teleports an exhausted Mikoto back to earth after she destroyed the AIM bomb. She is later seen asleep near Mikoto along with Uiharu, Saten, Kongou, Kinuho, and Maaya in the grounds of the Academic Assembly venue, most likely tired, as the Assembly begins in earnest.

As Janie and Febrie are in a Kongou Airlines runway, preparing to leave to the outside for body readjustments, Kuroko gives her the four leaf clover she found those many days ago for good luck. And thus, the fellowship, though bound by friendship and love, part ways.

#### Daihasei Festival Arc

*Main article: Daihasei Festival Arc (Railgun)*

Kuroko, Saten, and Uiharu appear right before Mikoto's competition in the three-legged race with her partner Kongou Mitsuko. Saten tells Uiharu of a substance known as Shadow Metal that is formed by the clashing of multiple espers, which can be sold for a large sum of money. Kuroko then appears right after, angry at Saten for spreading rumors again, to which forces her to distract and stay her anger by pointing out that Mikoto's competition is about to begin.

After the race, Kuroko is not present with the others as they meet Misaka Misuzu, explaining Kuroko's surprise in *Toaru Majutsu no Index* when she meets her later in the afternoon of the first day of the Daihaseisai. Kuroko doesn't reappear until after much later during the lunch break. She returns with Misaka Mikoto back to Judgment 177 Branch Office as the former have a bit of time before her next event. At the time Uiharu is communicating with Saten as she is in Kirigaoka Girls' Academy grounds in School District 18 looking for Shadow Metal. Immediately after, Saten is attacked by men in hazmat suits. Concerned, Mikoto asks Uiharu what is going on, to which he explains that Saten is being attacked by someone on the other line. Hearing this, Kuroko and Mikoto mobilized after Uiharu says that Saten is in Kirigaoka Girls' Academy grounds in School District 18. Uiharu is left behind for a backup as they might need to contact Anti-Skill. Arriving there, Kuroko notices them, but Mikoto, seeing Saten being held down angers Mikoto and attacks them. Mikoto and Saten later prostrate themselves in apology to them after it is revealed that they are the one who clean the grounds after an event to prevent the DNA traces of espers from being stolen by outsiders. Seeing Saten as a trespasser in the grounds, it was only natural for them to apprehend her. They are later let go by them.

Kuroko says that the rumors of Shadow Metal spread because of the fact that the grounds were heavily guarded to prevent DNA maps from being stolen, and berates Saten for being carried away by a baseless rumor, as well as Mikoto for the attack. The others later arrive back in the office, and much to Kuroko and Mikoto's chagrin, Saten then immediately asks Uiharu if she had found any new information. Uiharu then says that she has done some searching herself but couldn't find anything. Little did they know that Misaki paid Uiharu a visit and have read her memories that she and the others are Mikoto's friends, modified her memories so she forgets about the website and have her erase the data of it from her computer, and have programmed her to lead her and her friends to her on the next day.

Kuroko is with Mikoto during the Night Parade where Mikoto becomes as excited as a child when the Gekota float comes by.

The next day, she is with Uiharu and Saten for their patrols, completely unaware that Misaki has begun her move against Mikoto. Uiharu, as programmed by Misaki, takes Saten and Kuroko away from their proper patrol route. Kuroko realizes that they are in the wrong route, which surprises Uiharu truly believed she was going the right way. Then, Keitz appears behind them, pretending to be an outsider in need as a distraction. Misaki later comes out of an alley as they are distracted and uses her powers to freeze their movements, preventing Kuroko from using her powers, and later erases their memories of Mikoto. As Mikoto tries to escape Misaki's clique, she notices Kuroko, Uiharu, and Saten walk along by. She is relieved and comes towards them, but much to her horror, discovers that they too have been brainwashed by Misaki. Mikoto is greatly angered by this effrontery, but is unable to do anything even if she tries to convince them that she is truly their friend. Moreover, Mikoto has another event to partake in.

Kongou, fresh out of her latest event, later meets up with Kinuho and Maaya and later stumble upon Kuroko and the others. Kuroko later airs her frustration on Mikoto coming up to her, making an accusation, and then asking them if they were joking. This surprises Kongou, Kinuho, and Maaya, wondering if Kuroko and Mikoto had a fight. Back with Kuroko and the others, she wonders on how Saten and Uiharu knew Kongou. They point out to her that they met when they were visiting Kuroko in the hospital, though this confuses Kuroko as she is not close with Kongou. The others can only conclude that there was a mutual acquaintance but cannot remember who.