Luna is an illegally created homunculus who fled her homeland. Discovered under monster attack, she was rescued by Rud, who gave her shelter and the name Luna, as she previously had none. She possesses waist-length white hair, blue eyes, and the homunculi-characteristic gem embedded in her chest. Unlike others of her kind, Luna exhibits human-like emotions. Initially shy and nervous around others due to fear of discrimination if discovered, she is also prone to embarrassment.

Luna wields the rare skill [Identify], also known as "Judgement" or "Appraisal," enabling her to detect and analyze others' skills. This ability revealed Rud's two unknown skills, Life Conversion and Shield of Sacrifice, which were misunderstood and led to his expulsion from the Hero’s Party. She demonstrates proficiency in magic and exhibits rapid learning capabilities, potentially linked to her homunculus nature. Within Rud’s household, she takes on domestic roles like preparing meals and forms a close bond with his sister, Manicia. Luna encourages Manicia to confide in Rud about her fears of being a burden, helping resolve tensions between them. She consistently refers to Rud as "master" and develops a strong attachment to him.

Her character progresses from timidity to greater openness as she integrates into Rud’s household. She later encounters other homunculi facing conflict and assists efforts to aid them, showing a willingness to confront challenges related to her origins. Her background as an illegal creation and subsequent integration into a supportive environment underscore her journey towards belonging and acceptance.