Age: 15 Height: 168cm Position: Shooter Captain of B-Rank #2 Mikumo Unit. Uses Raygust, Spider, and Asteroid. With a Trion level of only 2, his mentor Karasuma even questioned if he truly belonged in B-Rank. However, through Karasuma's guidance and the Spider techniques he learned from Kitora, he developed a style that compensates for low power with ingenuity. He uses Spider tactics to shape the environment, making it easier for Yuma to fight while obstructing opponents.

Age: 15 Height: 141cm Position: Attacker Member of B-Rank #2 Mikumo Unit. Side Effect: Lie Detection. Uses Scorpion and Grasshopper. A rationalist and realist due to his survival experience since childhood and his father's teachings. While he is ruthless toward enemies, he shows great courtesy to benefactors and those he deems superiors, so he is by no means uncooperative. He possesses extraordinary combat ability based on practical experience gained as a mercenary and a wealth of adaptability.

Age: 14 Height: 140cm Position: Sniper Member of B-Rank #2 Mikumo Unit. Personality: Introverted and modest, fearing to cause trouble for those around her. Likes: Small animals, children, white rice, working. She boasts the absolute #1 Trion capacity in Border, but despite being a sniper, she has a psychological weakness: she cannot bring herself to shoot (or harm) people.

Age: 16 Height: 171cm Position: Attacker Possesses a serious personality that matches his stiff way of speaking. He has the observational skills to view things objectively and provides accurate tactical analysis. His swordsmanship is high enough to go toe-to-toe with the #6 Attacker Ikoma using Kogetsu. Upon his promotion to B-Rank, he added Viper and Escudo to his kit, apparently to fill gaps in Mikumo Unit. While Escudo normally consumes massive amounts of Trion, Hyuse handles it with ease due to his own high Trion capacity.

Age: 21 Height: 191cm Position: All-Rounder Captain of A-Rank Tamakoma First. The only All-Rounder in Border who can also handle sniper roles, earning him the title "Perfect All-Rounder." He has an extremely calm personality, embodying terms like self-possession and composure. Like Konami and Jin, he is a veteran member who has been with Border since the old days. Despite his physique, he is incredibly dexterous, capable of everything from combat and engineering to his hobbies of cooking and baking. He is entrusted with any situation, showing top-class skill in all, including brute-forcing with his specialized trigger "Full Arms" which exceeds the firepower of standard triggers. He gets uncharacteristically flustered around Yuri Rindo, another veteran from the old days.

Age: 16 Height: 178cm Position: All-Rounder A former member of Tachikawa Unit who transferred from HQ to Tamakoma a year ago, so he has many connections at HQ. He is often called "Torimaru" instead of Karasuma by those around him. Despite his cool appearance, he has a playful side, frequently teasing his senior Konami with lies. He is the eldest son of a poor family with five children. His style mainly involves gunfights while hiding with Escudo and close-quarters combat with Kogetsu. His original trigger, "Geist," allows him to shift into specialized modes by manipulating five parameters (Armor, Shoot, Speed, Special, Slash) displayed on his left hand, exerting immense power. He addresses Kuga as Yuma, Mikumo as Osamu, Amatori as Chika, Hyuse as Hyuse, Konami as Konami-senpai, Kizaki as Reiji-san, and Jin as Jin-san.

Age: 17 Height: 157cm Personality: Extremely competitive, proud, innocent, and easily deceived. Position: Attacker for Tamakoma First. Likes: Sweets, fruit, red things. An A-Rank agent of the Tamakoma Branch and the Attacker for Tamakoma First, boasting overwhelming strength as the #3 individual ranker. She is honest with herself and speaks her mind clearly, maintaining good relationships. She calls Karasuma "Torimaru" and is so gullible she believes his lies every time. Incidentally, her school grades are good. She is a high-mobility, high-firepower Attacker who uses Sogetsu as her main weapon, combined with Meteor in a Shooter style, and delivers massive blows with her unique trigger's connector mode. She addresses Kuga as Yuma, Mikumo as Osamu, Amatori as Chika, Hyuse as Hyuse, Karasuma as Torimaru, Kizaki as Reiji-san, and Jin as Jin.

Age: 19 Height: 179 Position: Attacker Side Effect: Foresight. S-Rank Agent. Between his Side Effect and his hobby of "maneuvering behind the scenes," he has an elusive, aloof atmosphere. He loves Bonchi Age crackers, keeping boxes of them in his room and often offering them to others. He is the user of the Black Trigger "Fujin," which allows for long-range slashes. Combined with his combat sense and Side Effect to read almost every move, he is a troublesome opponent who is difficult to even land a hit on. He refers to himself as a "talented elite." He addresses Mikumo as Osamu, Amatori as Chika, Hyuse as Hyuse, Karasuma as Torimaru, Kizaki as Reiji-san, and Konami as Konami.

Age: 17 Personality: Friendly, caring, and goes at her own pace. Position: Operator for Tamakoma Second. Honorary Chairwoman of the Border Glasses-Wearers Association. She owns six pairs of glasses: for daily use, work, reading, outings, sleeping, and a spare. She is not just tolerant of fashion glasses but actively encourages them, believing that glasses becoming fashion is a historical inevitability and a law of nature. She addresses girls with "-chan," boys with "-kun," and superiors with "-san."

5 years old. Tamakoma Branch. First person: I (childish/confident). Side Effect: Talking to animals. Height: 98cm. Black hair and black eyes. Often seen with the capybara "Raijinmaru." He addresses everyone without honorifics. He calls Kyosuke "Torimaru," Chika "Chika-chan," and Usami "Shiori-chan."