Rokurō Wakamura/Plot

Background
Wakamura joined Border approximately two years before Chika Amatori and Yūma Kuga. He joined Katori Unit through his friendship with Katori's brother. At some point he was tutored by Sumiharu Inukai in Gunner techniques.

Introduction Arc
Katori Unit was presumably involved in the extermination of all Rads in Mikado City.

B-Rank Rank Battles Arc
After Tamakoma Second's victory in the match against Suzunari First and Nasu Unit on Februray 8, Katori Unit drops to the middle tier of B-rank for the first time in two seasons, later dropping to 9th place when they lose to Nasu Unit.

Katori Unit is on defense duty on Wednesday February 19 and they make short work of a group of Mole Mods. When Yōko Katori complains about having defense duty on the day before a match, Wakamura retorts that it happens to all units and that she should watch the logs before complaining. The two begin to bicker until Hana Somei rebukes them.

Minutes before the match Wakamura looks over Tamakoma Second's files while Katori plays on her phone. He calls her out on becoming apathetic every time they lose, criticizes her for never making an effort and dropping anything that challenges her. She demeans his skill in turn, but he retorts that precisely because she is so much better than he is, she should stop quitting before even making an effort. Katori rudely dismisses him, and the rank battle begins. Katori goes after Yūma right off the bat, to Wakamura's frustration. Yūta Miura and he rush to support her, activating their Chameleon as they make their way towards Osamu Mikumo. Wakamura arrives just in time to protect Miura and Katori from Osamu's bullets. Katori warns him that Yūma is coming and Wakamura turns to intercept him, but the Attacker uses the invisible wires set by his teammate to dodge and nearly takes Wakamura out. He blames Katori for the damage they suffered, sparking a short discussion with her before they attempt to flee the wire zone. Wakamura attempts to cover their retreat, but he struggles to read Yūma's movements.

Tamakoma Second stops chasing them as soon as they leave the wire zone, but Kakizaki Unit is immediately onto them. When Kotarō Tomoe disrupts their formation, Kakizaki Unit gains the upper hand. Wakamura prevent Katori from charging head-on, but their defenses are gradually whittled down. Somei recommends moving to an open area to force Tamakoma Second, whom they know to want to score as many points as possible, to come to their aid. The combined fire prompts Kakizaki Unit to retreat and all three units separate to regroup. Wakamura reproaches Katori for acting on her own, which led to Miura and he taking damage to protect her. She retorts that they protct her because they would be unable to win without her. After their squabble Katori suggests ignoring Tamakoma Second and fighting Kakizaki Unit outside of the wire zone, with Wakamura approving of her plan and proposing an ambush. As the two units begin to converge, however, Chika starts to demolish the surrounding structures.

Wakamura is surprised that Katori does not know about Chika's firepower. Somei tells her teammates that they should ally themselves with Kakizaki Unit and go into the wire zone to pressure the Sniper with their numbers. Contrary to their expectations, the one who intercepts them is Osamu. Katori Unit makes their way to him while cutting down his wires, until their chase takes them to an area to which Chika has a direct line of sight, forcing them to take cover against her Lead Bullet sniping. Katori rejoices when Tomoe bails out, but Wakamura points out that if Kakizaki Unit falls, Yūma will come after them next. Katori Unit convenes not to take a detour but to take out Osamu first. Wakamura attracts Chika's attention while Katori and Miura charge at the enemy Shooter, but their offensive fails. Wakamura realizes that Tamakoma Second has anticipated all their moves.

Katori Unit is forced to shoot at Osamu from behind cover, essentially being stuck in place as they cannot understand how Osamu managed to make Katori trip. When Kuniharu Kakizaki bails out as well, Katori takes her frustration out on Wakamura. Somei tells her to distract Osamu while Miura and Wakamura circle around him. Wakamura trips as Osamu produces more red wires, and is taken out by his planted bullets.

When, after the end of the match, Katori has a meltdown, Wakamura is flabbergasted by Somei's incitement to her captain to quit Border, and even more so when Miura speculates that the reason that Katori is so angry is that she envies Tamakoma Second.