Toaru Majutsu no Index Episode 21

"Counter Stop" (正体不明(カウンターストップ)) is the twenty-first episode of the Toaru Majutsu no Index anime series, and the first episode of the Kazakiri Hyouka Arc. It was first broadcast on February 26, 2009, and was directed Yanagi Shinsuke, storyboarded by Yanagisawa Tetsuya, and the script written by Nishizono Satoru.

Touma's long summer vacation that began with his encounter with Index is ended and the semester begins. In Touma's class, Himegami Aisa who was freeloading in Komoe's house appears as a transfer student. Meanwhile, entrusted to stay at home, Index discovers that lunch wasn't provided for her and reaches Touma's classrom and is immediately kicked out by Komoe. She wanders towards the cafeteria and comes upon a vending machine. Predictably, she does not know how to make a purchase until she is aided by Kazakiri Hyouka, who appears casually before her. Their relationship deepens and Index becomes friends with Hyouka. In the peaceful Academy City, a magician is confirmed to have infiltrated the city.

Adapted From

 * Toaru Majutsu no Index Light Novel Volume 06

Major events

 * Academy City's second school semester begins.
 * Himegami Aisa tranfers to a certain high school.
 * Index and Touma meet Kazakiri Hyouka.
 * Shirai Kuroko confronts Sherry Cromwell but is unable to subdue her.

Characters
By order of appearance
 * Kamijou Touma
 * Index
 * Sphynx
 * Misaka Mikoto
 * Tsukuyomi Komoe
 * Himegami Aisa
 * Shirai Kuroko

New Characters

 * Musujime Awaki (Unnamed)
 * Sherry Cromwell
 * Kazakiri Hyouka
 * Yomikawa Aiho

Abilities

 * Teleport - Level 4, Shirai Kuroko.
 * Ellis Golem - Pratical Kabbalah, Sherry Cromwell
 * Electromaster - Level 5, Misaka Mikoto
 * Railgun - Level 5, Misaka Mikoto

New Abilities

 * AIM detection - Unknown. Hypothesized to exist by Touma.
 * Teleport (Move Point) - Level 4, Musjime Awaki.

Locations

 * Academy City
 * Kamijou Residence
 * A Certain Highschool
 * Windowless Building

New Locations

 * School District 7 Underground Shopping Center

Trivia

 * Due to Yamisaka Ouma's story being transferred to the second season of Toaru Majutsu no Index, a continuity error exists in this episode, specifically, Touma's room remaining intact, though this event is not mentioned again in the novels as well.
 * When Index picks up Sphynx and rolls around the floor, she once hums A Certain Tune.
 * This is the first introduction of AIM in the series.
 * The mysterious Imaginary Number District is introduced.
 * Telesma is first mentioned in the series.
 * Aisa being a girl who goes unnoticed, would later become a recurring joke in every Toaru Majutsu no Index-related media she would appear in. This would be prominent in the Toaru Majutsu no Index-tan specials, poking fun on her apparent lack of notability.
 * This marks the very first time espers and magicians, if one does not take Tsuchimikado Motoharu into account, do battle with each other.

Referbacks

 * Touma references his memory loss again back in episode 6.

Cultural References

 * The talk regarding AIM and detecting it, references common tropes in fighting manga and anime, most importantly, a character detecting and measuring another character's power.
 * The Golden Ratio is referenced by Index.
 * In the scene outside of school, after Aisa is focused on for the first time after her introduction to the class, and her noticing Touma and company, there are two background characters that walk by. The characters look similar to Fukuzawa Yumi and Ogasawara Sachiko of Maria-sama ga Miteru.
 * The popular For Dummies series of books is referenced during the episode as a book for learing about AIM dispersion fields.
 * Several terms from Jewish mythology and Kabbalism is referenced in this episode, such as the Golem, Noah's Ark, and the origin of Man, and their relations with angels. Mos specifically, the Grigoris are referenced.

Animation Trivia

 * Komoe's car is the only traditionally rendered during its appearance.
 * Mikoto would need to be pretty quick or the coin have been flipped very high, for her to make a pose for her Railgun.

Unanswered Questions

 * Is there really an esper that can detect AIM?
 * Who is that teleporter that came with Motoharu in the Windowless Building?
 * How does Motoharu know of the General Superintendent?
 * Who is Kazakiri Hyouka, and is she really a transfer student of a certain high school?
 * Why did Sherry infiltrate Academy City?

Quotes

 * Index: "What should I do... This is a huge crisis I have yet to face..." ―regarding her lunch plans.
 * Mikoto: "You think I asked you calmly?! Even for me, I didn't know what to do... and since I couldn't come up with any other solution... I swallowed the embarassment and... begged you to do it!" ―To Touma after he references the fake date they had.
 * Komoe: "Mmm... his Power Level is 70000!" ―On possible applications of an AIM detecting ability.
 * Aleister: "For it is a restive horse that could rip apart the entire world, and it would be best to have a firm grip of the reins before it's too late." ―To Motoharu regarding the Imaginary Number District.
 * Aogami Pierce: "Hey, look at me, I purposely left them on the backburner just so that Komoe-sensei could give me a scolding!" ―To Touma after he mentions Motoharu not doing his homework.
 * Komoe: "Congratulations, goons! Better luck next time, kitties." ―To the students of her class after saying that the transfer student is a girl.
 * Index: "Don't worry Hyouka. Touma's hot-blooded and indecisive, and if it involves girls, he's the type that'll dive right into problems for her, but he's a good person." ―To Hyouka, regarding Touma's personality.
 * Hyouka: "Animals are much more cunning than humans, so he could probably tell the difference between you and me." ―Regarding Sphynx jumping out of her bosom.
 * Komoe: "Why is it that girls always trickle down to you wherever you are, Kamijou-chan?!" ―To Touma after she discovers him with Index and Hyouka.
 * Hyouka: "Friends that are able to fight with each other are the ones that are really close." ―To Index.
 * Hyouka: "The fact they can fight means they can forgive each other properly afterwards. It's like you can trust that person to not cut off the relationship even after a fight." ―To Index.
 * Aisa: "I'm a girl who goes unnoticed after all, huh?" ―Aisa after Touma gives her a cold expression.
 * Mikoto: "Kuroko, it's okay to rely on me more. Don't think about not causing me trouble." ―To Kuroko after defeating Ellis.
 * Sherry: "In the beginning, there was primal clay. God created a form from the clay, bestowed life upon it, and called it 'Man'. This secret was passed to Man through the oral tradition of the fallen angels. However, this was a secret too great for Man to handle. Thus, the life born from my hand halts at a decaying mud doll. Mud-stinking golem, Ellis. Laugh and decay at my bidding." ―Sherry's incantation.