|This article is about a/an ally in Choujinki Metalder.|
2nd Sub-lieutenant Tatsuo Koga (古賀 竜夫 Koga Tatsuo?) is Dr. Koga's only son, whom Metalder was modeled after. He died in October 1944 as the first member of the Kamikaze Special Attack Squads. He loved music and played the violin with the potential to be a great violinist.