Despite knowing he doesn't stand a chance, Osamu decides to accept Sōya Kazama's challenge. After defeating Osamu multiple times, Kazama tells him that Jin gave Fūjin away so that Yūma could join Border. Hearing this, Osamu asks for one more round, this time managing to get a draw. After the battle, Yūma greets Osamu, and he has a short discussion with Kyōsuke Karasuma and Ai Kitora. Osamu and Yūma are then called to the Sniper's training area, where they find out Chika destroyed the wall. Rumors start to spread about the three newcomers, and Jin, told about that, says he already expected that.
Osamu and Kazama size each other up as the fight begins, but then Kazama disappears. Karasuma explains to Yūma that he is using Chameleon, and Kikuchihara remarks that since Trion doesn't run out inside the training rooms, Chameleon can be used limitlessly. Osamu looses over and over, but Osamu realizes that when using Chameleon, Kazama can't use other Triggers. He fires Asteroid around the room, trying to catch Kazama off guard, but Kazama appears and says he is used to this strategy, and once again defeats Osamu.
Kitora asks Karasuma to stop them, since there is no way Osamu can win. Yūma says Osamu probably knows he can't win but is instead gaining experience for the future. Kitora says that if he doesn't fight to win, he won't gain anything from the experience. Karasuma admits she makes a good point, but says it is up to Osamu and Kazama to decide when to finish. Just then, Kazama puts away his Triggers, having won over 20 times. Kazama then admits he expected more from Osamu and doesn't understand why Jin would give up his Black Trigger so his team could compete in the ranking battles (see Episode 16). Understanding that Jin gave up the Black Trigger made by his mentor's death, he asks Kazama for one more fight. Thinking he may not be able to win, he wants to hit Kazama at least once. Osamu remembers what Karasuma taught him about shooters and their ability to manipulate bullet performance, and that his sense can reflect thinking and planning strategy during the middle of battle. Osamu considers his four weapons (Asteroid, Shield, Raygust, and Thruster) and prepares for the final round.
Osamu fills the entire training room super slow-moving bullets in order to pull Kazama out of Chameleon. Kazama rushes at Osamu, thinking he will attempt one large shot, but Osamu surprises him by activating his Thruster instead and pinning him to a wall. Osamu then seals Kazama to the wall with Raygust, creates an opening, and fires Asteroid at point-blank range. Osamu appears to have lost, suffering a major hit to his shoulder. However, as the smoke clears, Kazama's Trion arm falls off, and round is declared as a draw. Karasuma remarks that although Osamu didn't win, it was a stunning victory.
Yūma meets Osamu as he exits the training room, and the two of them high-five. Karasuma meets up with Kazama and thanks him for fighting his pupil. Kazama then asks if Karasuma taught Osamu the final strategy, but Karasuma says that he only taught him some basics. When Karasuma asks what Kazama thinks of Osamu, he says Osamu is weak with low Trion level and can't see what Jin was raving about, but he has with and creativity to fight, which Kazama doesn't object to. Yūma asks Kazama for a fight, but Kazama declines, telling Yūma to reach his level if Yūma wants to fight.
Kikuchihara scolds Kazama for losing to "that," saying he would've won 100 out of 100 fights. Inwardly Kazama reflects on Mikumo's ability to completely read his moves after the first 20 rounds and is interested to see how far someone untalented can go with that kind of wisdom and creativity.
Arashiyama runs up to Osamu, quickly telling him there is trouble with his other teammate. Chika is on the floor, bowing in apology for blowing a hole in the side of the base. Azuma says that Satori will take responsibility since it occurred during training. Noting that Chika's Trion level hasn't been measured, he asks where she is from, and Chika worries that her actions will reflect poorly on Tamakoma Branch. Again, Azuma says Satori will take responsibility. Kinuta barges in, angrily demanding to know who blew the giant hole in the wall. Chika stands up, but Satori quickly jumps in front of her and takes responsibility. Chika ends up bowing on the floor again and admits she was the one responsible. Kinuta asks Azuma if this is true, and he confirms that Chika shot the hole with Ibis and she is from Tamakoma Branch. Osamu and Yūma rush into the room to find Kinuta kindly patting Chika on the head and praising her high Trion level. Azuma remarks that probably Chika reminds Kinuta of his daughter who lives far away. Seeing Osamu, Kinuta slaps him on the back several times and tells him to properly look after Chika. The other sniper trainees huddle excitedly around Chika as Yūma checks out the giant hole she made. Azuma realizes that Jin and Rindō most likely didn't report her amazing Trion level in order to make a spectacular debut at HQ.
Sitting among a large pile of smoking Trion Warrior remains, Jin receives a call concerning his attention-grabbing kouhai and says that even without his Side Effect he could tell they would be at the center of attention. At HQ, everyone is talking about the amazing new members, Chika, Yūma, and Osamu. During his phonecall, Jin says that this is just the beginning.