|Japanese:|| 蛟蛇 (こうじゃ)|
Koja was an A-Rank agent in the Striders, a Strider who moved at incredible speed thanks to plasma drivers installed in his body. He used a plasma-enhanced weapon known as a Cy-fang (サイ・ファング) in battle.
With a set of plasma drivers located in each of his extremities, Koja's speed was enhanced to superhuman levels. He made use of his boost in mobility to attack his targets at high-speed, slashing them apart with his weapon. Koja wore an entirely white armor and clothes, with the exception of dark blue leggings and a red mask. He carried the first kanji of his name, "ko" (蛟, dragon), as his personal emblem.
Koja was one of the 11 agents who infiltrated Kazakh City previous to Hiryu, carrying the mission to assassinate Grandmaster Meio. The unique magnetic field generated by the Gravitron units found within the city complex, however, affected his drivers and sealed his movements. In the end, Strider Koja went down unable to throw a single punch.
Koja's costume color scheme (white/dark blue) appears to be based off the color scheme of Sengoku BASARA's character Kotarō Fūma.
The first kanji in Koja's name can also refer to the "Mizuchi", a mythical dragon creature with an apparent affinity to water.