The Official Enlistment Day is finally here, and after Masafumi Shinoda and Arashiyama Unit explain how the event works, Yūma and Chika make a flashy debut at enlistment training, with Yūma beating the record in the Colossal Neighbor Simulation and Chika firing a shot strong enough to destroy the base's wall during Sniper training. After Yūma finishes the simulation in even less time after being challenged by another trainee, the No. 2 Attacker Sōya Kazama challenges Osamu to a Rank Battle.
Osamu, Yūma, and Chika arrive at Border HQ on Official Recruitment Day. Osamu is nervous even though, as Yūma points out, Osamu is already an official Border agent. After reaffirming their desire to form a team and aim for A-Rank, the official ceremony begins. Shinoda welcomes the trainees, all C-Rank. From there, Arashiyama Unit takes over, to the delight of most of the trainees. Next to Yūma; however, a group of boys scoffs, saying Arashiyama Unit is only chosen for their good looks in order to promote good PR for Border. Yūma and Replica note their ignorance.
The attackers and gunners are told to stay in the main hall, while the snipers are directed to follow Satori, and Chika waves as to Osamu and Yūma she follows the sniper trainees to the training hall. Arashiyama nods at Osamu and Yūma, then begins by explaining how the trainees can achieve B-Rank and thus becoming official Border agents. He directs everyone to look at the back of their left hands, where glowing numbers appear, indicating their skill in using Triggers. The trainees must use the one combat Trigger in their holder to raise that number to "4000" in order to pass. Some trainees have higher numbers, due to their recognized potential. Among these are the three boys who disparaged Arashiyama Unit earlier. Trainees can earn points by joining group training twice per week or by participating in ranking tournaments. As the group walks down the hall, Kitora approaches Osamu and asks why he is here, since he is already B-Rank. Osamu explains he is here to accompany Yūma and transfer registration. Kitora notices some kind of thing about Yūma, and he asks her how to get to B-Rank as fast as possible. She tells him to get a perfect score in every training and win in ranking tournaments.
First off is virtual combat against a Neighbor. During the simulation, trainees won't lose Trion or get hurt, and each person has a five-minute time limit. As the trainees proceed to take turns, Kitora and Osamu observe from above. Kitora remarks that a pretty good time would be under one minute. She asks how long it took Osamu his first time, but he is too embarrassed to say that he ran out of time and was disqualified. When the loud-mouthed boy from earlier finished in 58 seconds. The controllers remark that this crop of trainees isn't as skilled when compared to those who came previously (Kuroe: 11 seconds, Kitora: 9 seconds, Midorikawa: 4 seconds). Just then; however, Yūma's turn begins, and he astounds everyone by finishing in 0.6 seconds. The loud-mouthed boy demands that Yūma do it again, his score becomes 0.4 seconds. Kazama, Kikuchihara, and Utagawa observe and admit his skill. Kitora then realizes that Yūma was the one who defeated the Neighbor at Osamu's school. Just then Karasuma appears, and Kitora seems flustered. She blushes and asks Karasuma to coach her again, but Karasuma declines and asks her to one-on-one coach Osamu instead, leaving her speechless with jealousy.
At sniper training, Satori completely misses Chika, because she is so small. Satori then introduces the different kinds of sniper weapons: Egret, Lightning, Ibis. Chika is asked to shoot Ibis, the most powerful and difficult to aim. She asks if she has to run after shooting, and the trainers assure her that she doesn't have to run this time. While the other trainees laugh at her apparent naiveté, one of the trainers inwardly admits Chika is correct. Since this is a skill normally taught after achieving B-Rank, he wonders who Chika's mentor was. Chika finally fires and not only destroys the target, but actually blows a giant hole out of the side of the building.
The loud-mouth boy calls out to Yūma, claiming he has "passed" and invites Yūma to join their team. Yūma abruptly declines, and Arashiyama confirms that Yūma is instead joining Osamu's team. At this, Kazama appears and asks to challenge Jin's kouhai in the training room. Arashiyama objects, saying Yūma is just a trainee. But Kazama corrects him, saying the one he wants to check out is Osamu who is an official agent, so it shouldn't be a problem. Both Arashiyama and Karasuma encourage Osamu to decline, since Kazama is not only A-Rank but also ranked third overall. Despite this, Osamu resolves to become stronger and go on away mission, he accepts. Tokieda moves all the trainees out of the room, but Yūma asks to stay. Karasuma tells Osamu that he won't be able to win as he is now, and Osamu says he knows. With an impassive look, Karasuma simply tells Osamu to not strain himself.