Haruka's mother succumbed to a terminal illness during Haruka's childhood. Before her death, she gifted Haruka a hand mirror, which became Haruka's cherished memento embodying their bond. This mirror later serves as the emotional catalyst for Haruka's journey when it vanishes.

She imparted Japanese folktales to young Haruka, including stories of mythical fox spirits gathering neglected human belongings. These tales established the foundational mythology Haruka later recognizes upon encountering fox-like beings in another world.

Her death created lasting emotional consequences, fueling Haruka's adolescent detachment and strained relationship with her father. Unresolved grief resurfaces when Haruka rediscovers childhood memories through the magic mirror's visions, depicting family moments that reinforce the mother's psychological presence despite her physical absence.

The character exists primarily through Haruka's memories and emotional associations linked to the mirror. Her narrative function centers on motivating Haruka's quest and symbolizing themes of loss and remembrance.