Koji (コージ Kōji) is one of the two mechanics of the Earth Team. He is the IT specialist while Stan is the mechanic specialist. Before Don Wei poached them, the two partners used to work together in Miguel's workshop, the creator of the Whizzing Arrow.
Shy and non-combative by nature, he prefers to avoid conflicts, but his quick thinking has saved the Earth Team on many occasions. It was his idea for the 'clustered turbine' hyper-drive that allows the team's new racer, the Whizzing Arrow III, to be much faster than their previous racers. They affectionately call the Arrow III their "baby". After returning to Earth, he goes back to work for Miguel.
- Koji is named after Koji Morimoto, an animator and one of Japan’s premier anime directors.
- Koji almost died at the beginning of the first race of the Oban Cycle over neglecting the separating platform for a wrench. He was barely saved by Stan.