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 learned from Kitora, he developed a style that compensates for low ability with creative tactics. He uses Spider to manipulate the environment, making it easier for Yuma to fight or to hinder opponents.

Age: 15 Height: 141cm Position: Attacker Mikumo Unit, B-Rank #2. Side Effect: Lie Detection. Uses Scorpion and Grasshopper. A realist with rational thinking shaped by survival experience since childhood and his father's teachings. He is merciless toward enemies but shows deep respect to benefactors and those he considers superiors, showing he is not lacking in cooperativeness. He possesses extraordinary combat ability based on practical experience gained from life as a mercenary and a wealth of adaptability.

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

Age: 16 Height: 171cm Position: Attacker Possesses a serious personality that matches his formal tone. Has the observational skills to view things objectively and provides accurate tactical analysis. His swordsmanship is high enough to trade blows with the #6 Attacker, Ikoma, using Kogetsu. Upon promotion to B-Rank, he added Viper and Escudo to his arsenal, reportedly to fill gaps in Mikumo Unit's capabilities. While Escudo normally consumes massive amounts of Trion, Hyuse handles it with ease due to his own high Trion levels.

Age: 21 Height: 191cm Position: All-Rounder Captain of A-Rank Tamakoma First. The only All-Rounder in Border who can also function as a Sniper, earning him the title of "Perfect All-Rounder." He has an extremely calm personality, embodying terms like self-possessed and composed. Like Konami and Jin, he is a veteran member who has been with Border since the Old Border era.

Age: 16 Height: 178cm Position: All-Rounder A former member of Tachikawa Unit who transferred from HQ to Tamakoma a year ago, giving him 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 straight-faced lies. He is the eldest son of a poor family with five children. His primary style involves using Escudo for cover during gunfights and Kogetsu for close-quarters combat. His original Trigger, "Geist," allows him to specialize (shift) into specific roles by manipulating five parameters (Armor, Shoot, Speed, Special, Slash) displayed on his left hand, exerting immense power.

Kirie Konami Age: 17 Personality: Extremely competitive, high-strung/proud, innocent and easily tricked. Affiliation: Attacker of Tamakoma First. Likes: Sweets, fruit, red things. An A-Rank agent of the Tamakoma Branch and the Attacker for Tamakoma First. She boasts overwhelming strength, ranked 3rd individually. She is honest with herself and speaks her mind clearly, maintaining good relationships with many. A high-mobility, ultra-high-firepower Attacker who uses Sogetsu as her main weapon alongside Meteor in a Shooter style, delivering devastating blows with her unique "Connector" trigger.

Age: 19 Height: 179cm Position: Attacker Side Effect: Foresight (Future Sight) S-Rank Agent Between his Side Effect and his hobby of "secret maneuvering," he maintains a breezy, elusive atmosphere that makes his true intentions hard to grasp. He loves Bonchi Age crackers, keeping boxes of them in his room and frequently offering them to others. A user of the Black Trigger "Fujin," which allows for long-range slashes. Combined with his natural combat sense and Side Effect to read almost every move, he has a troublesome fighting style that makes it difficult for opponents to even land a hit. He refers to himself as a "talented elite."