Koji Minamoto (Japanese name: Kouji Minamoto) is the deuteragonist in the Digimon anime series Digimon Frontier. He holds the spirits of the legendary warrior of light, Lobomon.
In the English version, he is voiced by Steve Staley.
In the Japanese version, he is voiced by Hiroshi Kamiya.
Koji is a preteen boy with pale skin, long black hair which is tied in a ponytail, and dark blue eyes. He wears a blue jacket with yellow stripes on the sleeves over a yellow T-shirt with a blue neckline and sleeve trimmings, grey pants that end at his ankles, long blue socks, and white sneakers with blue stripes. On his head, he wears a blue bandana with dark grey stripes. His face is identical to his twin brother, Koichi.
Koji is a quiet boy who prefers to keep to himself. He starts off rather standoffish and doesn't think much of the abilities of others, but in truth, he is a shy and lonely boy who isn't sure how to approach others.
Koji was the child chosen to wield the Spirits of Light. Koji starts the series as the group loner, but gradually warms up to the others. Koji receives Ophanimon's cell phone message while he was out buying flowers for his stepmother. He followed the instructions on the SMS, which led him to a subway station where a Trailmon took him to the Digital World.
Koji traveled alone until he met Tommy Himi and J.P. Shibayama and had to save the two from a horde of attacking Pagumon. From then on, Koji showed up to help the other DigiDestined from time to time, and then eventually joins the group permanently.
Koji also meets his twin brother, Koichi Kimura, for the first time in the Digital World. Koji's parents had split up when they were too young to remember each other, and his mother had moved out with Koichi and their grandmother. Koji's father remarried, but lied to Koji, telling him that his mother had died, and never informed him of his twin brother. As such, Koji grew up never knowing he had a brother, let alone a twin. But he missed his birth mother very much (not knowing that she was actually still alive) and he would constantly look at a photograph of her that was on the backside of a framed picture containing his current family, something his father seemed to disapprove of. Despite his stepmother's kindness and the fact she genuinely cares about him, he had a really difficult relationship with her, not willing to accept her presence in his life. He actually finally decided to accept her as his mother on the same day he would unknowingly be sent to the Digital World, ordering a bouquet for her and his father's third wedding anniversary and making the decision to call her "mom". When he and the others returned to the Real World, he was able to fulfill his task, graciously presenting his wonderfully surprised stepmother some flowers. He was also later reunited with his birth mother with the help of Koichi.
- He is similar to Matt Ishida.
- His Japanese Voice Actor, Hiroshi Kamiya is best known voicing as Takashi Natsume from Natsume's Book of Friends and Levi Ackerman from Attack on Titians.
- His English Voice Actor, Steve Staley is best known voicing as Ryo Akiyama from Digimon Tamers, Neji Hyūga from Naruto/Naruto Shippuden, Kamui Shirō from X/1999 and Tōshirō Hitsugaya from Bleach.