|“||First the new models, and now a Black Trigger?! A man can't have a little rest 'round here?||”|
–Kōtarō Suwa, in Large-Scale Invasion 14.
Suwa has medium-length, messy hair dyed blonde, shaved on the sides and back of his head, and short sideburns. He has black eyes with small pupils. His unit's uniform is composed of an olive green jacket with black lines around the hem, the zipper and the high collar, and white ones running along the outer side of the sleeves and around the middle of the collar. There are two piped patch pockets closed by the same flap on each breast, and the B-rank logo is emblazoned above the left one while Border's is located on the outer side of both sleeves a little below the shoulders. The uniform also includes headphones which Suwa wears around his neck, a dark red undershirt with a V-neck, grey pants, a black belt with a dark grey pocket on the left side and dark grey boots with black spats. In his trion body Suwa is always seen with a cigarette in his mouth.
Suwa is loud, with a bombastic personality that reacts in a big way to everything. He is vulgar and assertive but very approachable and without pretenses, and quick to get comfortable around. When in combat, he has a tendency to be reckless and enjoys teasing opponents and riling them up, as he did with Enedra. He has a cigarette in his trion body to show off.
Suwa is the unifying force of his unit, raising his teammates' morale. They have a good relationship and hang out together outside of Border duty.[BBF Q135] Despite his penchant for gambling in battle, Tsutsumi trusts Suwa, while Sasamori deeply respects him. All his teammates address Suwa by his surname, presumably as a sign of respect, although they speak casually to him and Rui Osano has no qualms about teasing him. On the other hand, Suwa calls at least Sasamori by his first name.
Kazama and Suwa are of an age and part of the same group of friends, often going out eating and drinking together.[BBF Q134] On one such outing, Suwa got Kazama so drunk that the latter picked a fight with a postbox.[BBF Q45] For his part, Suwa is plotting revenge on Kazama for causing his name to become synonymous in Border with trion cubes.[BBF Q172] They address each other by surname.
Kazama, Kizaki, Suwa and Terashima are of an age and part of the same group of friends, often going out eating and drinkng together.[BBF Q134] Suwa addresses Kizaki by his first name, implying closeness.
Suwa is mahjong buddies with Azuma, Fuyushima, Tachikawa, who gather to play in Suwa Unit's operation room.[BBF Q71] Suwa is very informal around Fuyushima, calling him "old man" while praising his usefulness during Galopoula's blitz.
Suwa and Tokieda seem to be on good terms. The two were seen walking and talking together in HQ.
Suwa is very impressed with Yūma's skill and enjoys watching him fight. They seem to have grown close at some point after their units competed in a rank battle, since Yūma walked over to Suwa, Sasamori and Tokieda when he spotted them and let himself be playfully manhandled by the captain. Suwa refers to Yūma as the "albino shrimp".
Suwa addresses Karasuma by his first name, which might suggest they are close.
Suwa was annoyed with Osamu continuing to challenge Kazama after his 20th consecutive defeat, although he was so swept away by his ingenuity in the last fight that he ended up rooting for him.
Although he does not enjoy his name becoming synonymous with trion cubes, Suwa is relieved that it happened to him rather than Chika or Kitora.[BBF Q172]
- "First the new models, and now a Black Trigger?! A man can't have a little rest 'round here?"
- "Stupid A-rank! He makes it sound easy!"
- (To Enedra) "You don't know what's going on, do you? I can tell by that stupid look on your face."
- (To Enedra) "Come on, Mr. Black Trigger. Let's have some fun, just like you wanted."
- (To Enedra) "Oh, nice attack there. Hit me again, I dare you. C'mon!"
- (About Kizaki training Chika) "What?! How does physics work in that relationship?! What's that beefcake gorilla thinking?!"
- Suwa likes cigarettes, beer, meat, mahjong and mystery novels.
- The cigarette that is part of Suwa's trion body may not be a real one.
- Suwa has a driver's license.
- The author initially described a cube in Suwa's cover profile. He then went on to call him a male version of Izuho Natsume, as well as one of his favorite B-rank agents.