Kouta Fujiki is a fifteen-year-old God Eater who joins the Far East Branch on the same day as the protagonist. He hails from the Outer Zone, where his mother and younger sister Nozomi reside, and his deep devotion to his family is a driving force throughout his story. As an old-type God Eater, he wields an assault-type God Arc that previously belonged to Tsubaki, making him notable as one of the few to use a hand-me-down weapon. His personality is consistently upbeat, and he serves as the mood maker of the 1st Unit, frequently lightening the atmosphere with a cheerful and slightly flirtatious nature. Despite his energetic disposition, he struggles with concentration, often falling asleep during lectures and showing less diligence in academic settings. In combat his impulsiveness and willingness to take risks are evident, yet he excels in reconnaissance missions, demonstrating sharp instincts and skill when the situation demands.

His primary motivation is the safety of his family. When Director Schicksal reveals a plan to reset the world, Kouta initially hesitates to oppose it, hoping such an outcome might grant his mother and sister a chance at survival away from the Aragami threat. This internal conflict highlights his protective nature and the weight of his personal stakes. Over time his development sees him grow from a somewhat reckless newcomer into a more responsible figure, and by God Eater 2 he eventually assumes the role of captain of the 1st Unit. His key relationships revolve around his unit comrades, especially the protagonist, with whom he shares a bond forged on their first day as God Eaters, and his family members, whose well-being constantly influences his choices. His notable abilities include adept reconnaissance work, proficiency with his inherited assault gun, and a resilient spirit that allows him to survive dire situations, defying the narrative death flags often associated with his character type.