The ace attacker of Tamakoma Second (Mikumo Squad).
Age: 15
Origin: The Neighborhood
Position: Attacker
Weapons: Black Trigger "Yūma Kuga" + Scorpion, etc.
Personality: Nonchalant and easygoing, but cares deeply for his comrades and is quite calm.
Traits: Small build and agile. Possesses extensive combat experience honed in the Neighborhood.
Side Effect: The ability to detect lies.

The captain and shooter of Tamakoma Second.
Age: 15
Position: Shooter
Personality: Serious with a strong sense of justice, and cares deeply for his comrades.
Traits: Relatively low Trion amount and physical abilities.
Strengths: Uses intelligence, ingenuity, and tactics to face superior opponents.
Role: The brain and commander of Tamakoma Second.
Described by Yūma as a "demon of responsibility."

A sniper belonging to Tamakoma Second (Mikumo Squad).
Age: 14
Position: Sniper
Personality: Quiet and reserved, but strong-willed and hardworking.
Traits: Possesses an extraordinary amount of Trion.
Strengths: Overwhelming firepower due to her vast Trion reserves.
Weakness: Has a strong aversion to directly shooting people.
Goal: Aims to join the expedition force to rescue her brother and friend who were taken to the Neighborhood.

An elite agent belonging to Tamakoma Branch who calls himself a "top-class elite."
Age: 19
Position: Former Attacker
Personality: Nonchalant, composed, and caring.
Traits: Possesses combat prowess among the best in Border.
Side Effect: "Future Sight" – the ability to see a short distance into a person's future.
Former user of the Black Trigger "Fūjin" and a former S-Rank agent.

A Neighbor from Aftokrator who later joins Tamakoma Second as a member.
Age: 16
Position: Attacker
Personality: Serious and unsociable. Possesses a very strong sense of loyalty.
Traits: Has high Trion ability and exceptional combat sense.
Weapons: Kogetsu, Viper, Escudo, etc.
Strengths: Excels not only in swordsmanship but also in tactical insight.
Goal: To return to his home country, Aftokrator.

An A-Rank agent belonging to Tamakoma First.
Age: 17
Position: Attacker
Skill: The "No. 3 Attacker" with close-combat ability among the best in Border.
Weapons: Sōgetsu (axes) – two axes that can be connected to form a giant axe.
Personality: Competitive and hates to lose, but quite straightforward. Her emotions are easy to read, with a bit of a tsundere streak.
Traits: Despite her small stature, she possesses extremely high attack power and mobility, excelling in close-quarters combat.
Affiliation: Tamakoma First (team with Reiji Kizaki, Kyōsuke Karasuma, etc.)

An A-Rank All-Rounder belonging to Tamakoma First.
Age: 16
Position: All-Rounder
Personality: Calm and poker-faced. Caring, and actually has a playful side.
Traits: High proficiency in both offense and defense, with skill surpassing that of an A-Rank agent.
Weapons: Kogetsu, Asteroid, Viper, Escudo, etc.
Special Equipment: Geist for short-term ability enhancement.
Relationships: Disciple of Reiji Kizaki and mentor to Osamu Mikumo.

Captain of Tamakoma First and one of Border's top all-rounders.
Age: 21
Position: All-Rounder
Personality: Calm, collected, and serious. Caring.
Traits: Large, muscular build at 191 cm.
Skill: A "Perfect All-Rounder" capable of handling close, mid, and long-range combat.
Trump Card: Overwhelming firepower from "Full Arms."
Relationships: Chika Amatori's mentor.
Special Skills: Cooking and self-training.

A skilled operator belonging to Tamakoma Branch. A key figure who supports the members of Tamakoma Second from an informational standpoint.
Age: 17
Position: Operator
Personality: Cheerful, friendly, and caring.
Traits: A "glasses lover" who adores eyeglasses.
Abilities: Highly skilled in equipment operation and information analysis.
Past: Former operator of Kazama Squad.
Special Skills: Knowledgeable about Trigger technology and Neighborhood technology.