Haruue Erii

Haruue Erii (春上 衿衣) is a character introduced in the Toaru Kagaku no Railgun anime. She is a level 2 Academy City student and a Child Error.

Appearance
She is a young girl around the same age and build as Uiharu Kazari. She has a short, dark hair, where she has tied a few strands of them together in the left side of her head.

Personality
She is shown as shy and soft-spoken but kind girl, however, she is often times shows a little eccentricity, like suddenly staring into space or walking into a glass window. She is also fond of eating, and has shown to try eating something that seemed edible to her; her fondness for eating often causes her to get food she is eating on her mouth.

She has a tendency of ending most of her sentences with "nano," which is a feminine copula.

Background
She and Edasaki Banri were close friends in a Child Error orphanage they were in; they were both telepathic and would often communicate to each other with telepathy. Eventually Banri was transferred to another Child Error facility (presumably to the Advanced Education Department, where she would meet Kiyama Harumi) and promised each other they would meet again. Erii has a picture of Banri inside a locket as a reminder of her friendship with her.

She eventually enrolled to a school in the 19th school district, however, she began to hear the telepathic beckoning of Banri (as she was trying to wake up from her comatose state). Because of this communication with her, it caused an RSPK Syndrome occurrence whenever she would use her telepathic powers to communicate with her, some times causing damage.

She later transferred to Sakugawa Middle School, at the height of the Poltergeist Incidents.

Poltergeist Arc
When she first appears, she is looking for the locket that she had lost. She is aided by Tsuzuri

Several days later, she returns as a transferred from the 19th District of Academy City to Sakugawa Middle School and becomes classmates with Saten Ruiko and Uiharu Kazari. Their teacher decides to makes her Uiharu's roommate, which appears to please her quite a bit. Misaka Mikoto, Shirai Kuroko and Saten Ruiko help her move into Uiharu's apartment, and they become fast friends. That night they go to a Fireworks Festival, but their merriment is cut short when another Poltergeist incident occurs. This makes Kuroko suspicious of Erii.

The next day, Uiharu takes Erii to Nature Park, where Erii tells Uiharu that she is looking for a dear friend. With Misaka Mikoto's help, Kuroko discovers that Erii can sometime display powers beyond her normal level.

Erii is later taken into custody by MAR. Therestina, MAR's captain, tells everyone that Erii is incapable of causing the Poltergeist incidents, but Kuroko is still suspicious of her, and this strains her relationship with Uiharu. Erii later reveals that the person she is looking for is Edasaki Banri, a student of Kiyama Harumi who was subject to the test on the analyzing the overloading of abilities by Kihara Gensei.

After Therestina recovers Banri and the other children from Harumi's care, Erii is reunited with the still-comatose Banri. She is later kidnapped by Therestina along with the rest of the comatose children. It is then discovered that Therestina is the granddaughter of Kihara Gensei and that she plans to continue his experiments with the Ability Body Crystal in the hope of creating a Level 6 esper.

She is awoken by Uiharu, when they catch up to her, and se witnesses the battle between Mikoto and Therestina as well as the latter's eventual defeat. After the battle, she reassures Kiyama Harumi that Banri trusts her as well as her decisions. This allows Harumi to use the crystal to finally wake her students. Banri, using telepathy, thanks Erii for listening to her words.

Erii is later seen with Banri and the other children on the rooftop of a hospital. They are waiting for the blimp to broadcast their message to Kiyama Harumi. This is a present for her birthday.

Sisters Arc
Erii tells Uiharu, over the phone, that she will meet up with everyone after she vists the hospital.

Erii can later be seen along with Kuroko, Mikoto, Saten, and Uiharu in a picture on the wallpaper of Mikoto's phone. This is one of the pictures that were taken on the day when Erii first met everyone.

Silent Party Arc
Erii talks to her teacher about moving for the sake of Edasaki Banri who will soon be released from the hospital. She arrives late for the girls' "Study Session," actually just a small eating party, for this reason.

She later joins the other girls to visit Banri. She later makes her final preparations for the move. Then she later visits Banri again for her hospital release and shows to everyone the Sakugawa Middle School uniform that they gifted her many days ago. She then joins the party prepared for Banri, as Kuroko and Kazari go tend to Judgment business. Ruiko meets up with Erii in the restroom, where she mentions Erii's first day in Uiharu's apartment unit. Erii recalls her shy disposition back then, but she decides to be more confident with herself for Banri's sake to repay how much Uiharu has done to her over her stay in her apartment unit. Banri is the first to leave as she has a check-up to go to, while others wait for Kuroko and Kazari. The two later arrive to which Kazari gifts Erii with that taiyaki she gave to her when she was in the MAR research laboratory. Much to Kazari's shock, Banri had to come back for a last check-up, and Erii ends up receiving the box of taiyaki she bought for the two.

As the other girls bicker around Kazari's idea of giving taiyaki to someone who just had cake, Erii soon remembers that the box in her hands has the same taiyaki that Kazari gave to her back then. Erii weeps upon remembering this well-cheished memory and vows to Kazari that she will help Banri the way Kazari had helped her. Eventually, the reality that she would move far away from Kazari dawns on Erii, and she hugs Kazari tightly. Kazari, despite her best efforts to hold back her tears, and that they only met this summer, she eventually breaks down and cry.

As Ruiko comments on how childish Uiharu can be sometimes, Mikoto just lets Erii and Uiharu savor this moment.

Erii later pays a visit to the Judgment office where she meets Febrie. The other girls soon fill her up on Febrie's current situation, and Erii shows her concern about her next place to call home, as she is anxious that not all facilities may treat her nicely as they hoped. Fortunately, Mikoto was able to ask permission fom the Tokiwadai Dormitory Supervisor to take Febrie into Cypress Park, but the dormitory supervisor tells then that it would take five days to prepare the necessary papers for the transfer. Ruiko and the girls show their determination in taking care of Febrie during those five days, and Febrie is happy to hear about it, although she continues to ignore Mikoto, much to her despair.

Kuroko soon reminds Uiharu about the security meeting they need to attend for the upcoming Academic Assembly and the girls soon part ways with Erii, who was greeted with joy by Febrie, putting even more salt on the lonely Mikoto's wounds.

During the Silent Party, Haruue Erii and Edasaki Banri is somehow permitted by Yomikawa Aiho to ride with her in the Ekaterina II S towards the Academic Assembly venue where several Judgment members try to fend off armed and dangerous Powered Suits controlled with Diffusion Ghost. The mecha still in the form of a very large vehicle later swerves and hits the two mechas piloted by Kosako Shunichi and Madarame Kenji. After temporarily disabling them, Erii and Banri gets out of the truck. Erii tells tells everyone that a telepathic connection is being set up to compensate for the lack of communications devices, care of Edasaki Banri and the telepaths of Judgment. Erii and Banri are onscreen along with the other girls during the tense moment where Mikoto informs them that they need to find a way to stop the AIM bomb hurtling towards the city. Erii later bears witness to Mitsuko using her Aero Hand to propel the Ekaterina II S into the outer atmosphere to use as ammunition for Mikoto's Railgun in order to intercept the missile. She is seen with Kazari, watching the debris from the AIM bomb burn up in the atmosphere.

She briefly reappears on September 2, while looking at the sky together with Banri.

Freshmen Arc
She, Uiharu, and Saten appeared in the background of the color illustration of the scene where the members of the new ITEM sit in the restaurant.

Abilities
She is a Level 2 Telepath, and is shown to be able to communicate telepathically with other people. However, when exposed to certain frequencies, her ability can show powers above that of her normal level. Because of this, she was the target of Therestina's attempt to use the exposure of the Ability Body Crystal on her, so Erii can become a Level 6. In both Railgun's and Railgun S' anime booklets her ability is referred as passive.

Trivia

 * At first, she is thought to be a filler character unique to the anime series, making little to no impact in the story if she is taken out of the story of Toaru Kagaku no Railgun and, by extension, Toaru Majutsu no Index. However, her mention in the Toaru Kagaku no Railgun  manga rules out that claim. She can be seen in a picture on Misaka's phone's wallpaper. This is one of the pictures taken in.
 * Furthermore, she (alongside Uiharu and Saten) appear in the background of one of the colored illustrations from the New Testament Light Novel Volume 1 (behind ITEM), solidifying her existence in the Index universe.