Luna Jarashi is a beastfolk woman who works as an investigator at the Akira Tounome Detective Agency. She belongs to a cat-type beast race and has medium-length gray hair, yellow eyes, and visible animal ears. Her role within the agency focuses primarily on bodyguard duties and physically demanding jobs, making her the team member who handles heavy labor and direct protection tasks.

In terms of personality, Luna has a big-sister-like demeanor combined with strong initiative and a proactive attitude. She is warm and protective toward her colleagues, especially toward Shizuka Yakou, the agency's blind human office worker, for whom she acts as a dependable older-sister figure. Despite her tough and action-oriented exterior, Luna has a somewhat rough and careless approach to things, and she hides an endearingly clumsy and pure-hearted side beneath her confident surface. Her straightforward nature sometimes leads her to be blunt or hasty, but it comes from a genuine desire to help and support those around her.

Luna's primary motivation is her dedication to her work at the detective agency and her care for her coworkers. She is particularly invested in the developing romantic relationship between Akira Tounome, the invisible detective who runs the agency, and Shizuka Yakou. Luna becomes visibly anxious and emotionally involved in watching their slow-building romance, cheering them on from the sidelines while sometimes growing impatient with the pace of their relationship. She wants to see them happy together and actively supports their connection.

Within the story, Luna serves as a supporting character and a member of the agency's eccentric staff. Alongside Daichi Kikira, a blunt and unsociable human investigator, she provides practical support for the agency's cases and helps create a warm, familial office atmosphere. Her physical strength and combat ability make her valuable for fieldwork involving threats or heavy physical demands.

Key relationships include her professional bond with Akira Tounome, the agency's owner, for whom she works as a reliable field operative. She shares a warm, sisterly dynamic with Shizuka Yakou, offering her guidance and emotional support as Shizuka navigates both her work and her romantic feelings. With Daichi Kikira, Luna forms a collaborative partnership within the agency, their different strengths complementing each other during investigations.

Luna's development over the course of the series centers on her growing integration into the core team of the Tounome Detective Agency. She becomes more accustomed to working alongside Akira's unique invisible abilities and learns to adapt to the various supernatural cases the agency handles. Her protective instincts and sense of responsibility deepen as she becomes more involved in the personal lives of her colleagues, particularly as she watches Tounome and Yakou grow closer.

Her notable abilities are tied to her beastfolk nature, which gives her physical strength suitable for bodyguard work and physically strenuous tasks. She handles combat and protection duties that require durability and force. Beyond her physical capabilities, Luna possesses strong situational awareness and a practical, action-oriented mindset that allows her to respond quickly in dangerous situations. She does not have supernatural invisibility or other special powers like some other characters in the series, relying instead on her natural beastfolk attributes and her experience as an investigator.