Damian is an 18-year-old boy who is the son of the Martian north pole's guerrilla leader. At first, he mistrusts Joe and the others and even confronts and fights Joe, when Joe tries to meet the guerrilla leader for the first time. While fighting, he almost trips and falls in the mountains but Joe saves him and ends up getting captured. Later on, he helps Joe escape from the prison and also decides to join them. When Joe becomes the pilot of Tobikage, Damian pilots the Kurojishi. In one story, he falls in love with a female ninja who was originally sent to trap his friends, but she sacrifices her life due to his love.