Yuriko Tsumura is the mother of Ikuto, Honoka, Aoi, and Ichika Tsumura. After her husband's death when the children were young, she became the sole provider for her family. As a struggling single mother of four, she works multiple jobs yet still faces financial difficulties, requiring Ikuto to take part-time work. Her tendency to overwork lands her in hospitals frequently.

Despite these hardships, Yuriko consistently maintains a cheerful demeanor in front of her children, hiding her struggles to avoid burdening them. She exhibits a playful sense of humor, particularly directed at Ikuto, and prioritizes her children's well-being and aspirations. This is shown when she offers her savings for their education even while hospitalized, sacrificing personal resources for their future opportunities.

Yuriko is a kind, loving, and supportive parent, encouraging her children's dreams despite the family's poverty. She embodies traits of a wide-eyed idealist, maintaining optimism through adversity. Her physical appearance includes black hair reaching her chest and blue eyes.