TV-Series
Description
Kōtarō Suwa captains the B-rank Suwa Squad, having joined Border roughly three years before Yūma Kuga and Chika Amatori. He possesses light skin, an average build, and distinctive medium-length blonde hair shaved on the sides and back, with short sideburns. His trion body always depicts a non-functional cigarette for show. His standard uniform is an olive green jacket with specific piping, headphones worn around the neck, a dark red undershirt, grey pants, and dark grey boots with spats.

Personally loud, bombastic, and assertive, he reacts explosively yet remains approachable and lacks pretenses, warming quickly to others. Combat brings out recklessness and a penchant for taunting opponents, like his exchanges with Enedra. However, high-stakes scenarios or commanding agents outside his squad reveal a composed, mentor-like persona. He reassures peers under stress, like Osamu Mikumo, and assesses defeats pragmatically. Off-duty interests include cigarettes, beer, meat, mahjong, mystery novels, and he holds a standard driver's license.

As a Gunner specializing in shotguns, his primary Trigger is Asteroid, delivering high firepower with adjustable bullet spread for focused damage or area coverage, excelling at close range despite low accuracy and fire rate. His other Triggers include: Starmaker (places detectable markers using one shotgun), Bagworm (conceals trion signatures on Radar), and Shield (minimally used, typically focused to block sniper fire). His Border Briefing File parameters are Trion: 6, Attack: 9, Defense/Support: 6, Mobility: 7, Skill: 7, Range: 3, Command: 5, Special Tactics: 2 (Total: 45). He relies on shotgun power and teammate support to overwhelm foes at close range, surviving prolonged fights through tactical awareness rather than speed or reflexes.

His leadership emphasizes high-risk, high-reward strategies leveraging squad coordination, defeating upper B-rank squads like Kō Murakami's through combined firepower and obstruction. During the Large-Scale Invasion, his squad fought Aftokrator's initial Trion Soldier wave. Cubified by a Rabbit and restored, he immediately reengaged Enedra, luring the Black Trigger user into a training room. This contained collateral damage while analyzing enemy abilities, recognizing the need to prevent Enedra locating the exit panel and coordinating with Chameleon users for the eventual takedown, earning Suwa Squad an Excellent Distinguished Service award.

In the B-Rank Wars, his squad defeated Suzunari First but lost to Tamakoma Second and Arafune Squad. Against Arafune, he anticipated Tetsuji Arafune's trap and countered sniper fire with precise Shield deployment. However, Osamu Mikumo outmaneuvered him strategically, resulting in Suwa failing to score and his squad dropping to 10th place. His adaptability showed during Galopoula's blitz when Jun Arashiyama assigned him ground command due to seniority. He maintained formation discipline against Idras and delegated tactical planning to Masataka Ninomiya, showcasing collaborative leadership growth. Post-battle, he assisted in identifying foreign substances on agents for analysis.