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World Trigger Wiki

This article is about the character. For other uses, see Kei Tachikawa (disambiguation).

Only when two opponents are closely matched does passion really make a difference. If victory was decided by the strength of a person's emotions... There's no way I'd ever be No. 1.

Kei Tachikawa during Tamakoma Second's second rank battle in Nasu Unit 4.[1]

Kei Tachikawa (太刀川 慶 Tachikawa Kei?) is a character in the manga and anime series World Trigger, the A-rank leader of Tachikawa Squad and both the No. 1 Attacker in Border and the No. 1 agent overall. Due to his actions, he was an antagonist of the Black Trigger Capture Arc, but later becomes a supporting character.


Kei infobox.png

Tachikawa has medium length, wavy brown hair (gray in anime). His brown (gray in anime) eyes have an odd crosshatched design.

In trigger mode he wears a black trench coat, adorned with red pinstripes. The Squad emblem takes place on his shoulders. He also wears black pants and black boots.


Tachikawa is an arrogant person and as a result has carelessness, risk-taking and underestimating the enemy as his flaws. Also, he tends to be in his mind a lot and becomes anxious when an opponent is surprisingly more difficult. But by being in his mind he analyses the situation with the information that he acquires in battle.

He also acts like Jin, as they have a similar way of thinking, which makes him disliked by Miwa. Despite that, he's quite friendly outside of the battlefield. He likes to joke around, just like Jin. He has strong views of strength, seeing it as a product of strategy and strength. But unlike Jin, Tachikawa is very dedicated to ending a battle quickly and perfectly. Similar to a samurai he keeps a firm posture, and a habitual technique to persistently execute devastating blows. He can be seen as aggressive when fighting, due to the destruction of city property and the sacrifice of a squad member. Moreover, being blind due to his focus, he is unable to have a larger viewpoint of the situation and turn the battle into his favor.

However, this is good for 1v1s, because of his habit to lock onto an enemy. In summary, when Kei Tachikawa wears his trion suit, and wields his Kogetsu, resilient, powerful, precise, attentive, disciplined, logical, humorous, selective, observant, helpful, confident, reliable, and controlled are a few words that describe his personality.[1] He is harsh towards Murakami, possibly because he has high expectations for the prodigy.[4]

Sometimes, he might come off as insensitive, such as saying that feelings don't matter in battle as he would never be the number 1 in Border if that was the case.[5] However, he later corrects himself by saying that he does like battles with emotion, but feels attributing the results to emotions is like saying the loser didn't want enough to win.[6]


Yūichi Jin[]

Tachikawa happy for Jin's demotion.

Tachikawa and Jin have a similiar way of thinking, so they understand each other. Tachikawa thinks of Jin as a rival and looks forward to fighting with him to see who is the best attacker in Border. When they're not fighting he is quite friendly towards Jin.

Tachikawa Squad[]

Kōhei Izumi[]

He thinks very highly of Izumi, as they are teammates and friends. Tachikawa mentions that the second blade on their Squad emblem represents Izumi, while the other two are himself and his second blade.[7]

Takeru Yuiga[]

Despite the two being in the same Squad, Tachikawa thinks very lowly of Yuiga due to how he got his position in Tachikawa's team. The bias is so bad that Tachikawa put his second Kogetsu blade in the Squad's emblem before Yuiga himself.

Yuu Kunichika[]

Shūji Miwa[]

Miwa dislikes Tachikawa, because he is similar to Jin. Tachikawa, on the other hand, seems to not notice it and appears to like Miwa. Tachikawa also likes to tease Miwa.

Sōya Kazama[]

Mutual respect, although Kazama is one rank below. Both appreciate rice crackers and coffee, Kazama doesn't appreciate Tachikawa's attitude at times towards battle.

Haruaki Azuma[]

Kō Murakami[]

Kirie Konami[]

Tachikawa and Konami have a relationship of mutual respect and friendly rivalry. Despite being both top attackers in Border, respectively, they refuse to acknowledge either of them as superior to the other.[citation needed] As shown during Galopoula's invasion, however, Konami is annoyed by Tachikawa's careless and playful personality.[citation needed]

Ren Tsukimi[]

According to Daisuke Ashihara, Tsukimi is Tachikawa's childhood friend.


  • (To Yūichi Jin) "3 weeks until official enlistment day. During that time, I'll definitely defeat you, and recover the Black Trigger." [8]
  • (During Aftokrator's invasion.) "Right, right. Let's finish this before lunch." [9]
  • (During Tamakoma Second's second rank battle) "The strength of your feelings doesn’t matter. Power, strategy, and luck are what decide a battle. […] Only when two opponents are closely matched does passion really make a difference." [1]
  • (During Tamakoma Second's second rank battle) "Don't get me wrong, I love passionate battles. But, if you attribute the outcome of the match to passion, you might as well be saying that the loser just didn't want it enough." [6]
  • (About Suzunari First) "Murakami and Taichi would come to protect Kuruma no matter what. That's how Suzunari First fights as a Squad." [10]
  • (About Osamu Mikumo) "Mikumo's aim from the very start was to deplete Nasu's trion. On top of having Amatori escape to reduce the risk of being destroyed, he went in for another point. Now I see. He is really a ruthless guy." [11]
  • (To Takeru Yuiga) "Alright, listen. I'm gonna say something good. Look at our emblem. There are three swords, right? This first one is me, the second one represents Izumi, and the last one is... My second sword. In other words, you're still a novice, so no getting puffed up. [...] Kunichika, you're the crescent moon on the back." [7]


  • "Kei" (慶) means "to congratulate, to celebrate".
  • "Tachikawa" (太刀川) means "Tachi River".
  • He likes Udon, Mochi (Japanese rice cake), croquettes and winning in Ranks Battles.
  • According to Ashihara's Q&A,[citation needed] he has done a lot of stupid things outside of battle:
    • He read the word "Danger" [deyn-jer] as "Dangah".
    • He once thought a computer was broken when it was just unplugged.
    • He only ate the dried fruit on a fruit granola bar.
  • When asked in a Q&A if the reason why Tachikawa's eyes resemble a grid is because, "he burned the mesh for grilling his beloved mochi into his eyes", Ashihara said that's probably the reason.


  1. 1.0 1.1 1.2 World Trigger Manga and Anime — Vol. 12 Chapter 99 (p. 10) and Episode 45.
  2. World Trigger Manga and Anime — Vol. 13 Chapter 24 (p. 2-3) and Episode 13.
  3. World Trigger Manga Chapter 160 (p. 7)
  4. World Trigger Manga and Anime — Vol. 12 Chapter 103 (p. 8) and Episode 47.
  5. World Trigger Manga and Anime — Vol. 12 Chapter 99 (p. 10-11) and Episode 45.
  6. 6.0 6.1 World Trigger Manga Chapter 99 (p. 17)World Trigger Anime Episode 45World Trigger Manga Volume 12 (p. 17)
  7. 7.0 7.1 World Trigger Manga and Anime — Vol. 13 Chapter 109 (p. 13-14) and Episode 67.
  8. World Trigger Manga and Anime — Vol. 4 Chapter 31 (p. 3) and Episode 16.
  9. World Trigger Manga — Vol. 6 Chapter 48 (p. 8).
  10. World Trigger Manga and Anime — Vol. 12 Chapter 102 (p. 4) and Episode 46.
  11. World Trigger Manga and Anime — Vol. 12 Chapter 102 (p. 21) and Episode 46.


Trigger: Kogetsu  •  Viper  •  Asteroid  •  Meteor  •  Hound  •  Tomahawk  •  Senkū  •  Bagworm  •  Gimlet  •  Grasshopper
Side Effect:
e d vBorder
Commander in Chief Masamune Kido
Administration Eizō NetsukiKatsumi KarasawaKyōko SawamuraMasafumi ShinodaMotokichi KinutaTakumi Rindō
General Staff Mikhael CroninRaizō TerashimaSeiji Mizunuma
S-Rank Tsukihiko Amō
A-Rank Ai KitoraAsumi AmakuraFutaba KuroeHayato UnoIsami TōmaJun ArashiyamaKazuma SatomiKei TachikawaKen SatoriKirie KonamiKōhei IzumiKyōsuke KarasumaMai KitagawaMitsuru TokiedaNozomi KakoReiji KizakiRyō UtagawaRyūji SaekiShinji FuyushimaShirō KikuchiharaShōhei KoderaShūji MiwaShun MidorikawaSōya KazamaTakaaki KatagiriTakeru YuigaTōichirō MomozonoTōru NarasakaYōsuke YoneyaYūichi JinYukimaru Ichijō
B-Rank Atsushi HokariChika AmatoriDaichi TsutsumiFumika TeruyaHanao TsukimiHaruaki AzumaHidetaka KitazoeHiro KitazoeHisato Sasamori • Hitoshi Matsushiro • HyuseItsuki FujisawaKai MinamisawaKazuaki ŌjiKazuki KurauchiKazuto TonookaKeizō MamiyaKō MurakamiKōji OkiKōtarō SuwaKotarō TomoeKuniharu KakizakiMakoto Chano • Mamoru Tokiwa • Masakuni Hakoda • Masataka NinomiyaMasato KageuraMinoru HataMitsuya KoinumaNoboru KoaraiOsamu MikumoRei NasuRokurō Wakamura • Ryōgo Funabashi • Satoru Hayakawa • Satoshi Mizukami • Seiji Marui • Shinnosuke Tsuji • Shō Motegi • Sumiharu InukaiTaichi Betsuyaku • Takahiro Ebina • Takuma YubaTatsuhito IkomaTatsuya KurumaTetsuji Arafune • Tokiya Saitō • Tsuneyuki Okudera • Waka Utsunomiya • Wataru UrushimaYōko Katori • Yoshinobu Kera • Yoshito HanzakiYūichirō YoshizatoYukari Obishima • Yukito Otokawa • Yūko KumagaiYūma KugaYūta MiuraYutaka Kashio • Yūya Tsuchisaki • Yuzuru Ema
C-Rank Fumifumi SaotomeHidehide HinoeIzuho NatsumeTeruteru Kōda
Operators Aki HiyamiAn KobayakawaAoi Kusumoto • Asami Taya • Asuka Asagiri • Ayumu Hatori • Hana SomeiHaruka AyatsujiHaya Kittaka • Hazuki Nanao • Hikari NireKaho MikamiKarin YuitsukaMadoka UiMako HitomiMaori HosoiMegumi TokuraNono FujimaruRen TsukimiRika RokutaRin KagamiRisa MakiRui OsanoSaki KusakabeSakurako TaketomiSayoko ShikiShiori UsamiYuka KonYuri RindōYuu Kunichika
Former Border Agents Akane HiuraMirai HatoharaShin KazamaSōichi MogamiTadaomi KandaYūgo Kuga
Affiliated Personel RaijinmaruReplicaRinji AmatoriRuka ShinodaYōtarō Rindō
Squads Arafune SquadArashiyama SquadAzuma SquadChano SquadEbina SquadFuyushima SquadHayakawa SquadIkoma SquadKageura SquadKakizaki SquadKako SquadKatagiri SquadKatori SquadKazama SquadKizaki SquadKuruma SquadKusakabe SquadKōda SquadMamiya SquadMatsushiro SquadMikumo SquadMiwa SquadNasu SquadNinomiya SquadŌji SquadSuwa SquadTachikawa SquadTokiwa SquadUrushima SquadYoshizato SquadYuba Squad
Branches Hayanuma Branch • Hisama Branch • Suzunari BranchTamakoma Branch • Wataayu Branch • Yumite District Branch
Factions Kido FactionShinoda FactionTamakoma Branch
Triggers AsteroidBagworm • Bagworm Tag • Bail OutChameleon • Cobra • ConnectorDummy BeaconEgret • Enhanced Radar • EscudoFūjinFull ArmsFull AttackGeistGimletGrasshopperHornetHoundIbisIdatenKogetsu (Spear/Gen'yō/Senkū) • Lead BulletLightning • Makō • MeteorRadarRaygust (Shield Mode/Thruster) • RingSalamanderScorpionShield (Fixed Mode/Full Guard) • Silencer • Sōgetsu (Axe) • SpiderStarmakerSwitchboxTeleporter • Timer • TomahawkTrion BodyViper