Misuzu Midorikawa, a Japanese woman, met George Russell, Viscount Marble, during his business trip to Japan. She developed a connection with him, partly because her personality echoed that of his deceased first wife, Frances Russell. Misuzu bore their daughter, Lynn Russell, in Japan. She raised Lynn there before embarking on a journey to England so Lynn could meet her father. En route to Marble Mansion, Misuzu and Lynn suffered a car accident. To shield Lynn, Misuzu used her own body to protect her daughter. This act caused fatal injuries to Misuzu, though Lynn survived. Misuzu died shortly after; George Russell initially concealed the truth from Lynn to spare her immediate grief. Misuzu's deepest wish for Lynn was that she grow into a "true Lady," embodying courage, kindness, and grace. This aspiration became Lynn's guiding force. Misuzu left Lynn a symbolic keepsake, the "Lady's Key," a tangible reminder of her mother's hopes and Lynn's promise to persevere. Adaptations vary in portraying her parents' emotional response to her death, with some minimizing their anguish. Misuzu's legacy endures through Lynn's resolve to fulfill her mother's wish, influencing key decisions and serving as an emotional anchor throughout the narrative.