A captain of the Dianna Counter forces, later promoted to major. He is a repatriation convoy commander and a military hardliner. When Kihel (in the guise of Dianna) refuses to conquer the sunbelt territory by force, Ackman rebels against her authority and takes personal control over the Dianna Counter forces. He intends to set himself up as king of a new Moonrace nation on Earth.

Ackman realizes the error of his ways after Gym Ghingham attacks Earth, and pledges his life to Dianna in order to atone for his rebellion.