TV-Series
Description
Kei Tachikawa captains the Tachikawa Squad and holds the dual titles of Border's No. 1 Attacker and top-ranked agent overall. He joined during Border's formative years, receiving mentorship from Masafumi Shinoda, acknowledged as Border's strongest normal trigger user, and tactical guidance from childhood friend Ren Tsukimi.
Tachikawa sports wavy brown hair and eyes featuring a distinctive crosshatched design, both rendered gray in the anime. His trion body attire is a black trench coat with red pinstripes, bearing his squad emblem on the shoulders, matched with black pants and boots. His personality blends arrogance with analytical precision. Prone to risk-taking and underestimating foes in combat, he maintains a strategic mindset, assessing battles through collected data. This intense focus can narrow his perspective during engagements but sharpens his effectiveness in one-on-one confrontations. Outside of battle, he exhibits a friendly and humorous side, often joking in a manner reminiscent of his rival, Yūichi Jin, a similarity contributing to Miwa's dislike of him. Tachikawa holds firm convictions about strength, believing it stems from strategy and capability, not emotion. He explicitly rejects the idea that victory comes solely from passion, though he acknowledges its role in close fights. He clarifies that attributing outcomes purely to emotion disrespects the loser's effort.
Tachikawa's early Border career was defined by his rivalry with Jin. While Tachikawa possessed greater conventional combat strength, Jin acquired a Black Trigger through a 20-agent competition Tachikawa didn't enter, shifting their dynamic as Jin could no longer participate in ranked battles. During the Black Trigger Capture Arc, Tachikawa spearheaded the operation to retrieve Yūma Kuga's Black Trigger on Kido's orders, advocating for an immediate assault before Yūma mastered Border triggers. Jin intercepted Tachikawa's force en route to Tamakoma Branch. Persuasion attempts failed, leading to combat where Arashiyama Squad reinforced Jin. Tachikawa ultimately lost to Jin's Fūjin and retreated. He later expressed enthusiasm about resuming their rivalry when Jin considered relinquishing the Black Trigger.
In the Large-Scale Invasion Arc, Tachikawa defended Border Headquarters against Trion Soldiers, swiftly destroying Ilgars units. He aided Kō Murakami by eliminating three Rabbits using Kogetsu enhanced with Senkū. His contributions earned him a special-achievement award of 1,500 points and 1.5 million yen. During the B-Rank Wars Arc, he provided commentary on Tamakoma Second's matches. He analyzed Osamu Mikumo's tactics against Nasu Squad, noting Mikumo's "ruthless" strategy to deplete Nasu's trion. In squad interactions, Tachikawa tempered Takeru Yuiga's arrogance through self-deprecating humor about their emblem's symbolism, highlighting Yuiga's novice status. Tachikawa attended strategic meetings concerning impending invasions, where Jin privately warned Konami about a future vision of Tachikawa's defeat. When the forecasted invasion occurred, Tachikawa joined top attackers defending the expedition ship. Informed of Jin's prediction about his potential defeat, he reacted with excitement at facing powerful opponents. Against Gatlin and Rata, he coordinated with Konami, deliberately allowing himself to be trapped alongside Gatlin so Konami could strike both simultaneously—a maneuver leveraging Jin's foresight to their advantage.
Trivia notes include the meanings of his name ("Kei" signifying "to congratulate," "Tachikawa" meaning "Tachi River"). His preferences include udon, mochi, croquettes, and winning rank battles. Outside combat, he displays occasional absentmindedness, mispronouncing "danger" as "dangah," mistaking an unplugged computer for broken hardware, and eating only the dried fruit from granola bars. Creator Daisuke Ashihara humorously suggested his gridded eyes resulted from "burning the mesh for grilling mochi into his eyes."
Tachikawa sports wavy brown hair and eyes featuring a distinctive crosshatched design, both rendered gray in the anime. His trion body attire is a black trench coat with red pinstripes, bearing his squad emblem on the shoulders, matched with black pants and boots. His personality blends arrogance with analytical precision. Prone to risk-taking and underestimating foes in combat, he maintains a strategic mindset, assessing battles through collected data. This intense focus can narrow his perspective during engagements but sharpens his effectiveness in one-on-one confrontations. Outside of battle, he exhibits a friendly and humorous side, often joking in a manner reminiscent of his rival, Yūichi Jin, a similarity contributing to Miwa's dislike of him. Tachikawa holds firm convictions about strength, believing it stems from strategy and capability, not emotion. He explicitly rejects the idea that victory comes solely from passion, though he acknowledges its role in close fights. He clarifies that attributing outcomes purely to emotion disrespects the loser's effort.
Tachikawa's early Border career was defined by his rivalry with Jin. While Tachikawa possessed greater conventional combat strength, Jin acquired a Black Trigger through a 20-agent competition Tachikawa didn't enter, shifting their dynamic as Jin could no longer participate in ranked battles. During the Black Trigger Capture Arc, Tachikawa spearheaded the operation to retrieve Yūma Kuga's Black Trigger on Kido's orders, advocating for an immediate assault before Yūma mastered Border triggers. Jin intercepted Tachikawa's force en route to Tamakoma Branch. Persuasion attempts failed, leading to combat where Arashiyama Squad reinforced Jin. Tachikawa ultimately lost to Jin's Fūjin and retreated. He later expressed enthusiasm about resuming their rivalry when Jin considered relinquishing the Black Trigger.
In the Large-Scale Invasion Arc, Tachikawa defended Border Headquarters against Trion Soldiers, swiftly destroying Ilgars units. He aided Kō Murakami by eliminating three Rabbits using Kogetsu enhanced with Senkū. His contributions earned him a special-achievement award of 1,500 points and 1.5 million yen. During the B-Rank Wars Arc, he provided commentary on Tamakoma Second's matches. He analyzed Osamu Mikumo's tactics against Nasu Squad, noting Mikumo's "ruthless" strategy to deplete Nasu's trion. In squad interactions, Tachikawa tempered Takeru Yuiga's arrogance through self-deprecating humor about their emblem's symbolism, highlighting Yuiga's novice status. Tachikawa attended strategic meetings concerning impending invasions, where Jin privately warned Konami about a future vision of Tachikawa's defeat. When the forecasted invasion occurred, Tachikawa joined top attackers defending the expedition ship. Informed of Jin's prediction about his potential defeat, he reacted with excitement at facing powerful opponents. Against Gatlin and Rata, he coordinated with Konami, deliberately allowing himself to be trapped alongside Gatlin so Konami could strike both simultaneously—a maneuver leveraging Jin's foresight to their advantage.
Trivia notes include the meanings of his name ("Kei" signifying "to congratulate," "Tachikawa" meaning "Tachi River"). His preferences include udon, mochi, croquettes, and winning rank battles. Outside combat, he displays occasional absentmindedness, mispronouncing "danger" as "dangah," mistaking an unplugged computer for broken hardware, and eating only the dried fruit from granola bars. Creator Daisuke Ashihara humorously suggested his gridded eyes resulted from "burning the mesh for grilling mochi into his eyes."