Lillia Greyrat is a maid of the Greyrat household. Before joining the family, she served as a royal guard maid in the concubine palace of the Asura Kingdom, where she was trained in the Water God Style of swordsmanship and held the rank of an intermediate-rank swordsman. During her time there, she was injured in a battle against an assassin who targeted a princess; a poisoned short sword left her with lasting damage. Though her life was saved, she could never again run or exert herself with full strength, and the kingdom dismissed her from service. Seeking a new start, she traveled to the remote region of Fedoa and eventually answered an advertisement from a lower-class knight seeking a maid with experience in childcare and midwifery. That knight was Paul Greyrat, her former classmate from a swordsmanship dojo. Paul hired her, and she became the household maid for Paul, his wife Zenith, and their infant son Rudeus.

Lillia is a serious, loyal, and hardworking woman. Her years of guard-maid training instilled in her an emotionally reserved demeanor, but within the Greyrat family she gradually shows warmth and dedication. She is deeply grateful to those who treat her with kindness; after Rudeus intervened to save her life during a crisis, her initial wariness of him transformed into unwavering loyalty, and she resolved to repay him even by raising her daughter Aisha to serve him. Despite her composure, she also has a more impulsive, lustful side, which led to an affair with Paul during a period of tension in the household. That affair resulted in the birth of Aisha, and Lillia eventually became Paul’s second wife, a position that places her in a delicate dynamic with Zenith.

Her primary motivations center on maintaining harmony within the family and faithfully fulfilling her duties, sometimes at the expense of her own well-being. She is brave and resolute, willing to endure great hardship—such as contemplating a dangerous winter journey with her newborn—to avoid causing trouble for others. In the story, Lillia serves as a caretaker and stabilizing presence in the Greyrat home. After the family is scattered by the Displacement Incident, she remains at the family estate and later plays a key role in managing the household and raising the children. Her relationship with Rudeus evolves from one of respectful distance to deep mutual trust; with Norn, she shows the same maternal care she gives to her own daughter. With Aisha, she instills a sense of duty and gratitude toward Rudeus, shaping Aisha’s devotion to him.

Lillia’s notable abilities are rooted in her past training. She was a competent sword fighter of the Water God Style, a defensive and counter-oriented technique, but the lingering effects of the poison have permanently limited her physical capacity. She cannot fight at her former level, though she retains enough skill to protect the household if needed. Her true strengths lie in her expertise as a maid: she is knowledgeable in household management, childcare, and midwifery, skills that made her invaluable to the Greyrat family. Over the course of the anime, Lillia grows from a reserved, duty-bound former guard into a warm and integral member of the family, defined by her quiet resilience and fierce loyalty to those she loves.