Yūichi Jin and Arashiyama Squad vs. Border's Top Teams

Yūichi Jin and Arashiyama Squad vs. Border's Top Teams is a fight between Border agents, Yūichi Jin and Arashiyama Squad Versus Tachikawa Squad (except Takeru Yuiga), Kazama Squad, Isami Tōma of Fuyushima Squad, and Miwa Squad that happened in the Forbidden Zone on December 18th.

Prologue
Masamune Kido had ordered HQ top teams to get rid of Yūma and take his Black Trigger after Miwa Squad's failure. On their way to Tamakoma Branch, they face Jin, who refused to let them through. Before a battle ensues, Arashiyama Squad joins Jin's side.

Summary
Kazama Squad charges in to fight Jin while Arashiyama Squad provides cover fire. Yūichi Jin fends off Ryō Utagawa's scorpion attack and wounds his shoulder. Jin dodges a Senkū Kogetsu from Kei Tachikawa that destroys a couple of surrounding buildings. Tachikawa, Kazama Squad and three snipers continue attacking Jin, while Kōhei Izumi, Shūji Miwa, and Yōsuke Yoneya team up to stop Arashiyama Squad.

Miwa and Jun Arashiyama have a verbal confrontation before the physical battle takes place. Kōhei Izumi lures out Ken Satori by pretending to go on "Full Attack Mode". In the anime, Ai Kitora falls for the bluff and gives Satori the signal to fire, revealing his location. Satori fires at his own volition in the manga. Yōsuke Yoneya pursues Satori, and Kitora rushes to defend the sniper. Yoneya attacks Kitora and they tumble into an empty room.

Meanwhile, Tachikawa and Kazama trade blows with Jin. During the fight Jin avoides snipes from both Tōru Narasaka and Shōhei Kodera by using his side effect. Isami Tōma refuses to shoot Jin since his pride as a sniper prevents him from missing shots. Tōma leaves to assist Miwa squad against Arashiyama Squad.

Kei attacks Jin with Kazama squad supporting. Jin fends off their attacks and wounds Ryō Utagawa and Shirō Kikuchihara. Kazama figures out that Jin is just stalling for time and playing defence in hopes that everyone else will eventually retreat to base due to a lack of trion. After getting his plan exposed Jin goes on the attack. Jin activates Fūjin and decapitates Shirō Kikuchihara.

Kazama and Utagawa activate stealth mode while Jin continues to fight with Tachikawa. the Miwa Squad snipers provide cover fire. Jin leads Kei and the pursuers into an empty garage he uses the walls and the ceiling to deflect Fujin's blades and deal massive damage to Kei. Kazama and Utagawa then attack Jin. Jin uses the wall to split Utagawa in half, while Kazama clashes with Jin and uses mole claw to damage Jin's foot. Kei then attacks Jin, however Jin uses his last slash that he hid in the garage to damage Kazama and further damage Kei.

Jun gets shot with lead bullet by Miwa and uses teleport to escape. Kitora and Yoneya continue to fight in the building. Kitora uses wires to trap Yoneya and stab him in the abdomen. Yoneya pushes Kitora out the window before bailing out and Tokieda uses his shield to protect Kitora and himself from Izumi. Toma shoots Tokeida in the face and Kitora in the leg. Jun and Kitora meet up and tricks Toma into revieling his location. Kitora then decapitates Toma. Before finishing off Jun Kazama and Kei Bail out and Miwa and co are told that the operation is off.

Aftermath
Kido was still determined to get the Black Trigger. Shinoda threatened to intervene on Yūma's behalf if Kido were to continue. Kido responded with his own threat: the employment of Tsukihiko Amō. Shinoda was shocked that Kido would go so far, as a battle with Amō could potentially lead to the annihilation of the city. Jin approached Kido and offered him Fūjin in return for Yūma's safety and permission for Yūma to join Border, promising Kido that Yūma would be useful for Kido's ultimate goals. Kido accepted, ending the ordeal peacefully.