No. 1 Attacker: Kei Tachikawa

Short Summary
''Jin begins to fight the personnel sent after Yūma, particularly his rival Kei Tachikawa. Meanwhile, Shiori starts explaining to Yūma and Osamu about Border's Triggers and Jin and Tachikawa's rivalry. The Raid Team then divides, with Tachikawa and Kazama Unit going after Jin, assisted by three Snipers - Tōru Narasaka, Shōhei Kodera and Isami Tōma, while Arashiyama Unit takes care of Kōhei Izumi and the rest of Miwa Unit.''

Long Summary
Shiori teaches Osamu and Yūma about Border Triggers. Border stores Triggers inside small handheld holders. Triggers are actually small chips, and each holder can house up to eight different kinds of Triggers, allowing a user to employ both hands and switching between kinds. Shiori continues by describing different kinds of Triggers: Scorpion and Kogetsu. Meanwhile the battle between Border's top teams and Jin/Arashiyama Unit wages on with Jin deftly outmaneuvering his opponents.

Tachikawa takes a moment to confer with Kazama, who notes that Jin hasn't fired his Fūjin yet. Narasaka wonders about Arashiyama's sniper, and Kazama rejects Kikuchihara's suggestion to go after Yūma, since the rest of Tamakoma First is still at their base. Tachikawa decides to spilt their forces: Tachikawa, Kazama Unit, and the three snipers will go after Jin while Izumi, Miwa, and Yoneya stop Arashiyama Unit. Meanwhile, Jin and Arashiyama Unit also confer, deciding to preemptively split up to draw out their attackers.

Miwa confronts Arashiyama, demanding to know why they joined Tamakoma. Arashiyama explains that some people fight differently (than Miwa), and he believes Jin must have a good reason. Izumi activates his Trigger, and Kitora mentions that he is in attack mode. At a distance, Satori fires, but Izumi has already switched to defense in order to draw him out. Yoneya is dispatched to deal with him, and Kitora follows. The two clash in midair, and Kitora is knocked into a nearby building.

Elsewhere, Jin stands off against Tachikawa and Kazama. Their battle begins, and Jin not only deflects Tachikawa and Kazama's attacks, but he also dodges the shots fired by the snipers. Narasaka says they cannot avoid the fact that Jin will dodge their shots and asks Isami to join their offensive. However, Isami replies that his pride as a sniper won't allow him to shoot at a target he knows he cannot hit, and he decides to go meet up with Miwa. As he leaves, he remarks on how Jin has manipulated them into position. Jin continually retreats from his attackers, and Tachikawa again wonders what he is up to.

At Tamakoma Branch, Shiori also explains the Trigger Osamu used previously (see Episode 6), Raygust. It is the heaviest Trigger and used by Reiji. The No. 1 attacker at Border, Tachikawa, uses Kogetsu, and is considered Jin's rival. When asked who is stronger between the two, Shiori guesses probably Tachikawa is stronger. A few years ago, Tachikawa and Jin would rank first and second in battles, respectively. Because of Tachikawa's proficiency with Kogetsu, Jin worked with engineers to create Scorpion. As a result, their matches were even every since. Shiori further explains that although Black Triggers can typically only be used by a compatible person, Jin's could be used by 20 agents. Although they all fought for it, Jin came out on top. Tachikawa wasn't able to fight for the Black Trigger, because the Trigger didn't pick him.

Tired of chasing Jin, Kazama says they should head to Tamakoma Branch instead. At this, Jin unleashes his Fūjin on Kikuchihara, forcing him to bail out. As Jin faces Tachikawa, Kazama, and Utagawa, he sighs and says it's time for Plan B.

Adapted From

 * Chapter 26
 * Chapter 27

Differences Between the Anime and Manga

 * The scene when Jin decapitated Kikuchihara was censored in the anime, despite it not being his real body.