Manicia is Rud's younger sister; both siblings endured parental abandonment in childhood, forging an unbreakable reliance on each other. Afflicted by a chronic, debilitating illness, she remains confined indoors, dependent on constant care. This condition drives Rud's perilous quest for wish-granting labyrinth treasures to secure her cure.

Physically, Manicia possesses blue eyes and black or blue hair falling to her chest, typically adorned with hair ribbons and featuring a distinctive ahoge (hair antenna). This cowlick possesses unique sensory capabilities, moving autonomously to detect Rud's approach. Her illness contributes to a frail appearance, yet her beauty draws positive attention from villagers in their Avancia hometown.

Personality-wise, Manicia often perceives herself as a burden due to her health limitations, habitually hiding symptoms to prevent others from worrying. She exhibits profound devotion to Rud, occasionally displaying jealousy when other women interact closely with him, despite lacking personal romantic inclinations. Though initially socially isolated, she cultivates friendships, notably with Luna—a homunculus rescued by Rud—and later bonds with former members of Rud's adventuring party who relocate to Avancia.

Her development involves gradual health improvement through the application of two labyrinth treasures obtained by Rud. These artifacts significantly alleviate her condition. Concurrently, she achieves greater social integration, evolving from isolation to active participation in community life alongside Rud's expanding circle of allies.