Mama Yoshinaga is the mother of Futaba and Kazumi Yoshinaga. She maintains a quiet demeanor and finds pleasure in domestic pursuits like cooking and gardening. This calm exterior, however, conceals a capacity for sudden and formidable physical ferocity when provoked.

She shares a strong and deeply loving marital relationship with her husband, Papa Yoshinaga. Alongside this devotion, she nurtures a significant infatuation with the phantom thief Kaitou Hyakushiki, an affection that exists without undermining her primary dedication to her family.

As a central pillar of the Yoshinaga household, she regularly engages with the living gargoyle, Gar-kun, the family's guardian. Her presence is integral to the home's dynamic, which is often talkative and eccentric, and she provides a constant, nurturing foundation for her children.