Toaru Majutsu no Index Wiki
Toaru Majutsu no Index Wiki

A Certain Tune is a tune that is often hummed by characters in the Toaru Majutsu no Index and Toaru Kagaku no Railgun anime.


It is in 4/4 time and is often sung in light and comedic situations. It is often sung in a low pitch, although, a higher pitched version is not unheard of.[1]

Variations of how it hummed are often present depending on the character, such as Mikoto singing in a higher pitch.[1]


Toaru Majutsu no Index[]

The tune is first heard being hummed by Index in the form of Aogami Pierce due to the Angel Fall effect, just before being strangled by Kamijou Touma.[2]

Much later, the tune is once again hummed by both Aogami Pierce and Tsukuyomi Komoe during the cold opening of the first episode of Toaru Majutsu no Index II.[2] Later in the season, both Index and Orsola Aquinas hum it at the same time during the scene where Touma is forced to decide which door is the one that doesn't have either of them taking a bath that would lead to some hijinks.[3] The tune is once again heard during Index and Accelerator's short ride with Orson, as Index reads a perverted version of the Ugly Duckling.[4]

In an anime original scene in the first episode of Toaru Majutsu no Index III, Index is seen singing the tune adding the lyrics "ofuro" (bath) to it as she and Sphynx bathed in the shower.[5]

Toaru Kagaku no Railgun[]

Misaka Mikoto hums this in the very first scene of the episode with a different pitch.[1] Later in the season, Touma hums the tune in the post-credits scene just before he meets Mikoto near a certain vending machine.[6]

In an anime-original scene in the first episode of Toaru Kagaku no Railgun T, Mikoto hums the tune in the very first scene of the episode.[7]



v  e

Index Openings PSI-missingmasterpiece
Endings Rimless ~Fuchinashi no Sekai~Chikaigoto ~Sukoshi Dake Mou Ichido~
Inserts Amejellyfish
Index II Openings No buts!See visionS
Endings Magic∞worldMemories Last
Inserts Pray ~Inori~
Index Movie Endings FIXED STAR
Inserts Telepath ~Hikari no Tou~ATARIMAE no KyoriBrand New Bright StepGloriaAshita, Hareru KanaOVERShining Star-☆-LOVE Letter
Index III Openings GravitationROAR
Endings Kakumei Zen'yaOwaranai Uta
Railgun Openings only my railgunLEVEL 5-judgelight-
Endings Dear My Friend -Mada Minu Mirai he-Real Force
Inserts SMILE -You & Me-
Railgun OVA Openings future gazer
Endings Special "ONE"
Railgun S Openings sister's noiseeternal reality
Endings Grow SlowlyLinks
Inserts stand stillInfinia
Railgun T Openings final phasedual existence
Endings nameless storyAoarashi no Ato de
Inserts Koko ni Itai
Accelerator Openings Shadow is the Light
Endings Parole
Games Openings ANSWER (Index PSP) • way to answer (Railgun PSP) • adverse wind (Index MMO) • Get Ready! (Virtual-On) • JUNCTION (Imaginary Fest) • Worlds Collide (Imaginary Fest)
10th Anniversary Where I belong... Zutto
Compilation Albums Index Compilation Album (Snap out of it!!) • Railgun Compilation Album
Artists Kawada MamiIKUKurosaki MaonfripSideELISAKishida Kyoudan & THE Akeboshi RocketsTHE SIXTH LIEsajou no hanaIuchi Maiko
Index OST 1Index OST 2Index II OST 1Index II OST 2Index Movie OSTpolarisIndex III OST 1Index III OST 2Railgun OST 1Railgun OST 2Railgun S OST 1Railgun S OST 2Railgun T OSTAccelerator OSTVirtual-On OSTVirtual-On Sound CD
Archives (Drama CDs & Image Songs)
Index Archives 1 Audio Drama"Arigato" no Keikenchi (Index) • Watashi Rashiku Aru Tame no pledge (Misaka Mikoto)
Archives 2 Audio DramaZero Kara no Gyakushū (Kamijou Touma) • Owari wa Dochira (Himegami Aisa)
Archives 3 Audio Dramaunder the cry (Stiyl Magnus) • Salvia farinacea (Kanzaki Kaori)
Archives 4 Audio DramaHisoyakana Yokubō ~Misaka wa, Hasseisase masu~ (Misaka 10032) • i intersect (Kazakiri Hyouka)
Index II Archives 1 Audio Drama"Okaeri" no Zettaichi (Index) • Gensou, Moshikuha Sore ni Hitoshii mono (Kamijou Touma)
Archives 2 Audio DramaShoudou nano de gozaimasu yo (Orsola Aquinas) • Stray Virgin (Agnese Sanctis)
Archives 3 Audio DramaBEAT IN (Biri)! BEAT IN (Biri)! (Misaka Mikoto) • Hi ~yun! DESTINATION (Shirai Kuroko)
Archives 4 Audio DramaNetwork wa Fantastic (Last Order) • 99.9% Noisy (Accelerator)
Railgun Archives 1 Audio DramaRailgun Girl Days (Misaka Mikoto) • Desu no! White & Black (Shirai Kuroko)
Archives 2 Audio DramaUbuiro Bloomy (Uiharu Kazari) • Namida Gomen no Girls Beat (Saten Ruiko)
Archives 3 Audio DramaGira Gira Now! (Misaka Mikoto & Shirai Kuroko) • Kanpeki Will (Uiharu Kazari & Saten Ruiko)
Non-Archives Toaru Majutsu no Index Radio DramaToaru Majutsu no Index III Drama CDToaru Kagaku no Railgun T Drama CDToaru Matsuri no Triangle
A Certain TuneBand ScoreKaraoke Song Numbers