Nina administers swordsman license issuance for the Tribe of Shadow. This kemonomimi character displays feline traits: dark purple fur, a tail, animal ears, orange wavy hair reaching her waist, yellow eyes, and fair skin. Her typical attire includes a collar, bell, and apron.

Her friendly and kind personality fuels a longstanding secret romantic affection for Astral. Motivated by these feelings, she assists him in obtaining a swordsman license against regulations. After Astral rescues her from a monster, she confesses her feelings, initiating a physical relationship that results in pregnancy. She gives birth to their daughter, Ariadne. Following Astral's disappearance, Nina raises their child alone while awaiting his return.

Her relationship with Astral evolves from administrative support to romance and parenthood. She later reveals Astral's paternity to Ariadne, demonstrating protectiveness as a mother. Ariadne's significance emerges through her mixed Light and Shadow Tribe ancestry, positioning her to fulfill a prophecy by deciphering the Words Worth tablet. During later conflicts, antagonists abduct Nina and Ariadne to prevent the prophecy's fulfillment.

Across adaptations, her core narrative remains consistent. The game includes a potential romantic conclusion with Astral, while the anime streamlines her involvement for central plot progression. Supplementary media like the Gaiden/Outer Stories OVAs and omake content expand her role, depicting comedic rivalry with Sharon and Mew for Astral's attention in post-war scenarios. Her character development transitions from supportive administrator to the mother of the child pivotal to resolving the tribal conflict.