J. Katayama

J. Katayama is a maintenance worker in Doom 3 who was stationed in the Caverns area. He is one of the few personnel who survived the initial invasion of Hell. The Marine finds him in the thermal regulation pumps, hiding away from the demons and refusing to come out until he was sure that all of the demons are dead for good. Katayama offers the Marine his key card, and pushes him to get out quickly since the Marine is making too much noise. He is the last survivor the player meets before the ending of the game.

His fate is ultimately unknown, but he presumingly perished along with the whole of Mars Base, as Resurrection of Evil states the Marine was the only known survivor of Hell's invasion.