Hikaru Makiba works her family's Japanese countryside ranch alongside her father, Danbei Makiba, diligently caring for their animals. Her life shifts dramatically upon meeting Duke Fleed, who arrives posing as Daisuke Umon. She develops romantic feelings for him but grows suspicious of his frequent disappearances. Discovering Duke's true identity as a prince from the destroyed planet Fleed and the threat of the Vegan Empire, Hikaru chooses to fight for Earth. Initially needing rescue, she evolves into an active combatant piloting the Marine Spazer, a support vehicle for Grendizer. Her piloting skills advance rapidly, allowing direct aid against Vegan forces. Hikaru acts responsibly within her family, managing her father's antics and caring for her younger brother, Goro. She maintains a close bond with Duke, supporting him emotionally and in combat. She interacts with Koji Kabuto as a friend, navigating his occasional flirtations, and later forms a friendly connection with Duke's sister, Maria Fleed, introducing her to ranch life. In the manga *Grendizer Giga*, Hikaru encounters Daisuke Uryu, who undergoes memory alterations. She demonstrates protectiveness towards him, using soccer skills to deter bullies and expressing frustration when he neglects farm duties. Her athletic background consistently includes horseback riding and gymnastics. Her appearance evolves throughout the series, starting in rural attire like a sun hat and skirt, transitioning to a yellow sweater and practical pants. As a pilot, she wears a form-fitting suit with a matching helmet. Following the Vegan Empire's defeat, she bids Duke and Maria farewell as they depart for Fleed. The name "Hikaru" signifies "light" or "brightness," while "Makiba" relates to herding or ranching, reflecting her family's livelihood.