Joshua is Ray's brother and is talkative, upbeat and sociable. Though he deeply cares for Ray, he is entirely different in behaviour than his older brother. Joshua claims his brother changed to his present behaviour after his wife, Yoshimo's, death at the hands of the Claw Man, and although he also loved Yoshimo, he wishes for Ray to accept her death and return home instead of exating his avenge on her killer. Joshua has great technical skills, being able to repair numerous everyday items, analyze armor weaknesses, and even set up timed explosives.
He matures rapidly after Ray's death, cutting off the connection between the claw's armor and the planet destroyer system. After The Claw's death, Joshua helps Van with finding a new orbital port for DANN. He tell Van that he and Yukiko are going to search for Volkain's remains, even though it might take many years.