Dr. 300X commands the Hikarians from the Hikarian Station and is addressed universally as "Doctor" by the team. His primary role centers on scientific innovation and technological development; he designed and constructed all Hikarian equipment, including the mobile Hikarian Station. He maintains a generally gentle and calm demeanor but reveals strong determination when necessary. While composed, he displays a tendency toward irritability under pressure—though less pronounced than Captain Hikari’s. He supports his assistant Windash with leniency, exemplified when he lifted Windash’s spirits by taking him to a Hikarian Station event. This action inadvertently disrupted antagonist Black Express’s trap due to logistical constraints. In combat, he carries a magnetic shield, though it remains unused throughout documented events. His scientific work extends beyond the core team through collaboration with Dr. Yellow, an engineer at Hikarian Headquarters who assists him.