Kokuyō stands as a tall, slender figure with striking curves and an imposing aura, embodying both grace and authority. As a divine attendant and priestess to the water goddess Kukuri, she balances shrine rituals with perilous missions to neutralize curses. Her crow-like wings grant flight, though hunger often saps her stamina, leaving her weakened mid-task.

A ravenous appetite defines her, driving her to consume staggering amounts of food in one sitting—a habit that drains shrine finances and strains relationships. To offset debts, she labors in construction and cashier roles, yet her hunger persists, bartering meals for aid or devouring entire feasts during assignments.

Prone to mistaken identity, she struggles to recall human faces. A detailed sketch of Kazuya Kagami fails to prevent her misidentifying Shirou Shiramine, a confusion recurring in later encounters. Social missteps follow, such as awkward apologies involving physical contact—a habit influenced by Shirou’s own blunders.

Summoned by Kukuri after the goddess’s power waned post-Kanaka Kagami’s defeat, Kokuyō aids in shrine restoration and debt negotiations, often worsening fiscal woes. When the shrine collapses, she relocates with Kukuri to Kazuya’s home, assisting his training and adapting to domestic life.

A mission to recover rogue tsugumomo nearly claims her life, leaving her gravely wounded until Taguri Kanayama intervenes. This injury shifts her dynamic with Kazuya, whose protective concern stirs unspoken emotions. She later proves instrumental in collaborative strategies against Kukuri’s foes, navigating dream realms and diplomatic tensions with tactical precision.

Subtle cracks in her stoicism reveal growth: offering heartfelt thanks through hesitant touch, softening at Kazuya’s worry, or betraying vulnerability in fleeting smiles. Though duty-bound, these glimpses hint at depths beyond her role—a warrior navigating loyalty, survival, and fragile human bonds.