Hyuuga, a former Silver Knight, now serves as an Aube Hunter fiercely dedicated to protecting Angelique. He initially maintains rigid formality, addressing her as "Angelique-sama," a reflection of his disciplined past and profound sense of duty. Only after Angelique directly orders him to use her name, declaring them friends, does he attempt to adjust, though ingrained habits make the casual address a persistent struggle.

His primary combat role involves wielding a spear against Thanatos, the life-draining monsters plaguing Arcadia. He diligently practices his spear skills outside the Sunlit Mansion during downtime, ensuring constant combat readiness. A significant, undisclosed event from his past involves leaving the Silver Knights after killing a fellow knight named Carlyl.

During the second season's events, Hyuuga experiences seasickness while traveling, a vulnerability he ultimately conquers. This period also witnesses the destruction of the Hidamari mansion. Alongside the other Aube Hunters, blamed by many for the surge in Thanatos, he endures a six-month vigil awaiting Angelique's awakening from unconsciousness. Throughout this ordeal, his unwavering focus remains solely on Angelique's safety. His dedication to her protection is absolute, extending to a readiness to sacrifice his own life if necessary.