Akari Hinobori, mother of Hajime Hinobori, possesses long red hair and blue eyes, typically dressed in a low-cut black dress with a white jacket featuring two floral decorations. She openly expresses deep affection for her husband Mahiru Hinobori, whom she endearingly calls "Darling," and demonstrates unwavering devotion to her son Hajime's happiness and well-being.

To fulfill Hajime's dream of witnessing real Battle Spirits, Akari collaborated with Mahiru to develop a specialized battle field system enabling realistic spirit manifestations during card battles. Later, she and Mahiru traveled to Germany for a business trip focused on advancing this technology. Their work resulted in system enhancements unveiled during the Hero Championship's national tournament. During their absence, they entrusted Hajime's care to fellow scientist Denjiro Tatsumi, involved in the battle system's development.

By the series' conclusion, Akari steps away from laboratory duties to begin maternity leave, expecting another child. Her character design includes moments where she stores cards in her cleavage, contributing to her visual portrayal.