Toaru Majutsu no Index Wiki

"Voice" ( Koe?) is the twenty-first episode of the Toaru Kagaku no Railgun anime series. It was first aired on February 27th 2010.


Toaru Kagaku no Railgun E21 02m 42s.jpg
Toaru Kagaku no Railgun E21 03m 59s.jpg

After the earthquake that occurred in Academy City during its fireworks display event, Kuroko and Mikoto meet up with Therestina, whose MAR units began to assess the situation. Kuroko mentions the deductions Mii plotted out regarding the connection of the earthquakes, RSPK and AIM diffusion fields with each other. Additionally, she points out that Judgment was being left out in the investigation by not being told about this connection.

Their conversation was interrupted when Saten and Uiharu told them that Erii will be taken to the hospital. Because of the Tokiwadai Dormitory's strict rules on curfew, Mikoto and Kuroko are forced to go home.

Toaru Kagaku no Railgun E21 06m 21s.jpg
Toaru Kagaku no Railgun E21 06m 34s.jpg

Back at Tokiwadai's dormitory, Kuroko was informed by phone that Erii has returned to her dormitory safely. Meanwhile, Mikoto is busy researching on the Level Upper case. She points out that the recent earthquakes has somewhat reminded her of Kiyama Harumi, who they know was still detained (in District 17's special prison). Kuroko decides to share her worries as well; she noticed how Haruue acted when the last earthquake occurred. Mikoto also remembered Saten talking about the rise of Poltergeist incidents in District 19 (where Haruue was before transferring) and Kuroko added that there are no similar events happening in District 19 recently. Instead, they happen in District 7. Kuroko suspects Erii to be the culprit for the Poltergeist, but Mikoto defends her, saying what's going on is just a coincidence. Meanwhile, at Uiharu's dormitory, Saten and Uiharu watch over Haruue as she rests. Uiharu remarks that Erii has no memories of what happened and was explained as a 'light state of shock' by the doctors back at the hospital.

Toaru Kagaku no Railgun E21 09m 10s.jpg

After Saten leaves for home, Erii finally awakes. She thinks she is the cause of the earthquake, but Uiharu defends her and tells her that she will back her up. Uiharu prepares the watermelon Saten brought earlier and as Erii continues to brood over what happened and being strange, Uiharu assures her that help is around, just like how she managed to join Judgment.

Toaru Kagaku no Railgun E21 10m 23s.jpg
Toaru Kagaku no Railgun E21 10m 49s.jpg

The next day, Uiharu leaves work to have time with Haruue, much to Saten's disappointment. As she gets picked on by Mii inside Judgment's Branch 177 headquarters, Mikoto and Kuroko continue their research on Erii's background, with the help of Mikoto's electricity.

Information on Haruue states that she is a 1st Year student from Sakugawa Middle School and a Level 2 Power User. Her ability is Telepathy. Mikoto rejoiced on seeing her profile, but Kuroko points out that there are notes on her ability: Has been known to exhibit power above her Power Level when subjected to specific wavelengths.

Toaru Kagaku no Railgun E21 11m 07s.jpg
Toaru Kagaku no Railgun E21 13m 28s.jpg

Back at Academy City's nature park, after an exhausting boat ride (since Uiharu is left rowing the boat), she and Erii took a rest on the riverside benches. While eating sushi rolls, Erii decides to be open and tells Uiharu that she was looking for a friend whom she hasn't seen for a long time. Uiharu reassures her and volunteers to help her.

All of a sudden, Haruue begins to mutter words and completely ignores Uiharu as if she was looking for someone. Just then, a boat passing by floats in mid-air, followed by another earthquake.

Judgment receives the report while MAR goes to the scene. As MAR continues their rescue operation, Therestina remarks that what happened was indistinguishable from a real earthquake.

In a hospital in District 5, Mikoto, Kuroko and Saten went to see Uiharu, who manages to acquire little injuries after the incident. Because of what she and Mikoto discovered back at the Judgment headquarters, Kuroko confronts Uiharu about Erii being a telepath, which Uiharu sees as 'a cruel move'.

Therestina soon appears with her findings that a telepath is involved with the interference of AIM diffusion fields. Although the girls knew of only one telepath (Erii), Therestina assures them that only a Level 4 telepath can create such an effect, though she added that they need to examine Erii to confirm their findings. This and Kuroko's eager participation enraged Uiharu for the first time.

Toaru Kagaku no Railgun E21 14m 13s.jpg
Toaru Kagaku no Railgun E21 16m 30s.jpg

At the MAR Base Research Laboratory, Kuroko and Uiharu are still at odds with each other regarding Erii, and Saten and Mikoto can only watch and do little to calm them down.

Therestina announces that the test is finished and asks them to come along with her to her room. As Mikoto glares with joy at the colorful figures of animals displayed in Therestina's room, the orange-haired researcher admits that those were part of her hobby.

Toaru Kagaku no Railgun E21 17m 29s.jpg
Toaru Kagaku no Railgun E21 19m 01s.jpg

After a short introduction from Therestina herself, Uiharu goes straight into the topic of Erii's involvement in the Poltergeist incident, which Therestina responds by giving her a yellow candy picked randomly from a candy tube, which is the same color that Uiharu says when she was asked to pick out a color. Therestina smiles and remarks that it was a good sign.

Meanwhile, a sneak peek of Kongou Mitsuko is shown, also asked to be examined because of her Level 4 Power Level.

Toaru Kagaku no Railgun E21 19m 51s.jpg

Later on, the girls and Therestina move to another room, one which holds Haruue in a device similar to an MRI machine. After the results are seen by Therestina, she tells them that she is not responsible for the interference. Kuroko still can't believe about Haruue being discounted from the incident, but Mikoto still wonders who the culprit is, if not Erii.

Toaru Kagaku no Railgun E21 21m 08s.jpg
Toaru Kagaku no Railgun E21 21m 38s.jpg

Later on, Haruue is taken to a room, where she wakes up and sees the four watching over her, with Therestina behind them. Haruue remarks on hearing her friend's voice before going in a daze, the friend being the one whose picture is in her locket.

Also, for the first time, she shows the face of her friend, whose name is Edosaki Banri. Mikoto instantly recognized it as one of the Child Errors Kiyama Harumi taught before.

Then, Erii admits that she is a Child Error as well.


New Characters

No notable new characters were introduced in this episode.

Adapted From

This is an anime-original episode, thus it is not adapted from a manga volume nor a light novel volume.



New Abilities

No new abilities were introduced in this episode.


Cultural References

  • On Uiharu's computer during her search, you can briefly see some icons for Saikoriosoft Autolock, Saikoriosoft Sentence, and Saikoriosoft EXL, clear parodies of Microsoft Access, Microsoft Word, and Microsoft Excel.
  • When Uiharu talks about negative ions in her discussion with Saten over the phone, she might have been talking about negative air ionization therapy, which is supposed to counter depression. It's considered pseudoscientific, so Uiharu might have said this to placate the urban legend-loving Saten.


# Title Time Scene & Notes
Unverified Track Opening
Unverified Track
Unverified Track Eyecatch
Unverified Track
Unverified Track Ending
Unverified Track Preview

Unanswered Questions



This section requires expansion
EN/JP(K/R)[Prev Ep]



v  e
Toaru Majutsu no Index Index 123456789101112131415161718192021222324
Index II 123456789101112131415161718192021222324
Index III 1234567891011121314151617181920212223242526
Index-tan 1234567
Toaru Kagaku no Railgun Railgun 12345678910111213141516171819202122232413'OVA
Railgun S 123456789101112131415161718192021222324OVA
Railgun T 12345678910111213141516171819202122232425
MMR 123456
Toaru Kagaku no Accelerator Accelerator 123456789101112
Bonus 1
Movies • Specials Miracle of Endymion10th Anniversary PV
Home Video Releases IndexRailgunAccelerator