Yoshiko Ikawa lives with her family in Tokyo. In her youth, she was a beautiful cheerleader whose features prefigured her daughter Noriko's appearance. Significant physical changes occurred over time, resulting in a heavier build due to uncontrolled eating habits and an evolved appearance characterized as elderly and sour-faced.

She is the mother of Tsuyoshi, Keiko, and Noriko. Yoshiko exhibits clear favoritism within the family, openly favoring her daughters Keiko and Noriko with greater affection, attention, and praise, while frequently neglecting Tsuyoshi. She metes out physical punishment to Tsuyoshi, smacking him without provocation and verbally berating him, contrasting sharply with her non-violent treatment of her daughters. Despite this harsh dynamic towards Tsuyoshi, she displays protective instincts towards all family members, aggressively confronting external threats.

Her marriage to Hideo Ikawa is portrayed as largely stable and fulfilling, though she occasionally behaves snappishly or violently towards him. During Hideo's extended business trip to Fukuoka, she remained in the family home while Tsuyoshi managed household responsibilities. Yoshiko combines domestic assertiveness with moments demonstrating care for her family's well-being. She participates in family milestones like birthday celebrations, expressing concerns about aging during them.

In official media extensions, Yoshiko appears in the 1993 movie where the Ikawa family discovers a time machine, travels twelve years into the past, and encounters their younger selves.