|This article is about a/an ally in Choujinki Metalder.|
- "Even if you are a robot, you don't have to act like one. (君はロボットにしてロボットに非ず。 Kimi wa robotto ni shite, robotto ni arazu.)"
- ―The final message to Metalder.[src]
Dr. Ryuichiro Koga (古賀 竜一郎 Koga Ryūichirō?) is a leading authority in Robotic Engineering, and the man who created Metalder. After World War II, Dr. Koga went to America and became a staff member at NASA. He returned to Japan when he learned of the existence of the Neros Empire and its ties to his past actions, prompting him to activate Metalder. Battered from Strobe's attempt on his life, Koga makes it to his secret laboratory and awakens the android from his rest. Soon after, in order to give Ryusei a sense of purpose, Koga allows himself to be killed by Chuubo and the Neros Empire members at the end of the first episode.