He is a middle-aged man with short, blond hair with gray strands by the sides of his hair. He has blue eyes and a square faceshape. He wears a blue suit, adorned with different military medals.
Jack is shown to be a busy, responsible and secretive individual, as he never told Vert about his real occupation. He deeply cares about his son and feels uncomfortable with Vert driving with the Teku, so much at the point of discouraging him to drive. Jack always told to his son that the duty always comes first, even if he had to choose between the two most important things on his life.