Kirihime Natsuno is a best-selling novelist writing under the pen name Shinobu Akiyama. Her life intertwined with Kazuhito Harumi during a café robbery where he died shielding her from a gunman, an event that burdened her with profound guilt. After Kazuhito's reincarnation as a dachshund, she adopted him and discovered a unique telepathic link allowing her to understand his thoughts, forming the core of their relationship.

She possesses long dark hair with straight bangs, red eyes, and a slender build, consistently dressed in all-black attire: a formal shirt, short skirt, thigh-high boots, stockings, and a longcoat. A constant companion is her pair of durable silver scissors, "Hasajiro," holstered on her left thigh since childhood. These scissors function as both tools and weapons, capable of cutting through materials like steel cages or projectiles. Kirihime is notably self-conscious about her small bust size and reacts aggressively to comments on it.

Her personality is complex, often appearing aloof, domineering, and sadistic. She intimidates Kazuhito with Hasajiro, punishing him for perceived slights or remarks about her appearance. Despite this harsh exterior, she harbors deep care for him, becoming fiercely protective and jealous when others interact with him. Her guilt over his death surfaces in vulnerable moments, including tearful breakdowns when discussing the incident. She gradually develops romantic feelings for Kazuhito, though he remains largely oblivious due to his singular focus on books.

Dedicated to her craft as an author, she prioritizes reader satisfaction above all. She lives alone in a studio apartment and maintains a professional relationship with her editor, Suzuna Hiiragi, whose masochistic tendencies complement Kirihime’s sadistic behavior. Beyond her scissors, Kirihime possesses significant physical strength and fighting proficiency, enabling her to parry bullets, defeat groups of attackers, and engage in combat with skilled opponents like Sachi Moribe.

Her relationships evolve throughout the story. Initially antagonistic towards Kazuhito’s sister, Madoka Harumi, who resented her for "taking" Kazuhito, their dynamic shifts toward mutual respect, culminating in joint activities like hot-spring visits. Kirihime also mentors Hami Ōsawa, a shy aspiring writer, after defeating her in a literary contest and validating her talent. Her interactions frequently blend menace with underlying warmth, defending Kazuhito from external threats while simultaneously tormenting him herself.

Kirihime’s character development involves reconciling her guilt over Kazuhito’s death, learning to express kindness indirectly, and navigating her unrequited feelings. Her journey highlights contradictions: a violent yet protective nature, emotional vulnerability masked by aggression, and a commitment to both her profession and Kazuhito’s well-being.