Yasuko Kusakabe is the mother of Satsuki and Mei Kusakabe and the wife of Tatsuo Kusakabe. She is hospitalized with tuberculosis, a serious lung disease, which is the primary reason the family has moved to the countryside in 1950s Japan. Her illness limits her physical presence in the story, but she remains a deeply felt emotional center. Her personality is gentle, calm, and hopeful. She consistently tries to reassure her daughters about her recovery, speaking to them with warmth and avoiding any show of worry. She is compassionate and nurturing, maintaining a bright and motherly demeanor even while confined to a hospital bed. Her main motivation is to recover and return home to her family, and she draws strength from her love for them. She also encourages their imaginations, telling Satsuki and Mei about the spirits she hopes to meet when she is well again.

Her role in the story is crucial despite her few on-screen appearances. The entire family’s move to the countryside and the daily life they build are driven by the need for her to be near a hospital with fresh air and sunlight. Her absence places a heavy responsibility on Satsuki, who steps into a caregiving role for Mei, and it also allows the girls’ magical encounters with Totoro to become a source of comfort and hope. Yasuko’s postponed visits create the film’s central emotional tension, especially when a setback in her treatment upsets Mei and leads to the crisis of Mei running away. The resolution, in which the girls reach her hospital and leave an ear of corn as a gift, reaffirms the family bond and her eventual return home.

Her key relationships are defined by love and mutual support. With Satsuki, she shares a connection of understanding, noting that Satsuki is very much like she was at the same age. With Mei, she is a source of unconditional affection, and Mei’s desperate desire to see her drives the climax of the story. With her husband Tatsuo, she has a supportive partnership; he handles the household and children during her illness and keeps the family’s spirits high. Her development is subtle: while she does not undergo a personal transformation, her resilience and hopefulness serve as a steady anchor for the family. She demonstrates no extraordinary or supernatural abilities; her strength lies in her emotional constancy and the love she inspires in those around her.