Fourth Kind is a large, wide-set man with, as a result of his Quirk, four arms. He has a buzzed, grayish-brown hair and small eyes with no eyebrows, although the skin where they’d be is notably heavy and defined. His teeth are prominently straight, and he also has a stitched scar running diagonally over his left eye.
His hero costume consists of a plain black suit (altered to include four sleeves) with a cyan-colored tie, three yellow diamonds patterning it down the centre, and a thick gold ring on each of his twenty fingers. His jaw also appears to be made of metal, or at least have a metal casing, as with his neck.
Fourth Kind is a strict professional who didn't cut Eijiro Kirishima or Tetsutetsu Tetsutetsu any slack during their internships. Any small infraction deeply upset Fourth Kind, who would reprimand the young men by hitting them. Tetsutetsu feared Fourth Kind's impatience would lead to punishment when Eijiro made them late one day.
Fourth Kind first appears when Eijiro and Tetsutetsu meet at his agency for their field training. The Chivalrous Hero explains his agency put in two offers because he was impressed with the guts they both showed at the sports festival. He informs them that they can't be heroes with force alone, but they interrupt him while he's talking so he yells for them both to be quiet. Then he goes on to explain the mechanisms of his salary and they're his office's practical operations.
Later on, he has both of them make him tea. When he tastes that it's too warm, Fourth Kind gets angry and punches both of them while their Quirks are active. He tells them that the tea needs to impress their clients, and then says it's satisfying to hit the interns' Quirks.
After the incident in Hosu, Fourth Kind catches Eijiro and Tetsutetsu coming in late. He angrily hits them and reminds them of the importance of punctuality. He also takes the boys to do community service by cleaning up a park.
He is mentioned by Eijiro, who attempted to intern under him again, but he was busy.
Katana: A katana is seen in his office, but it is unknown how proficient he is with it. It is likely that his katana is purely decorative in nature.