In 1949, Chihiro remarried to Zenmei Matsumoto, a young man who was seven and a half years her junior, and bore their only child, a son named Takeshi. During the period when she left Takeshi in the care of her parents in Nagano Prefecture so she could work and support the family, Chihiro often traveled 7 – 8 hours to see him. Her experience as a mother enabled her to draw masterful illustrations of babies and children in different ages.
In her works, Chihiro searched for innovative means of expression, exemplified by the creation of the so-called "feeling picture books," which place the emphasis on illustrations over text to provoke empathy.
Also, in a time when copyrights were still not established, Chihiro asserted the rights of authors by demanding that publishing companies return her original illustrations. As a result, she retained a large number of her original works, which eventually led to the establishment of the world's first picture book museum.
As an artist committed to children's happiness and peace, Chihiro was deeply pained by the war in Vietnam, and in 1972 she began working on her book Senka no Naka no Kodomo-tachi (“Children in the Flames of War”). The book also reflects the artist's own wartime experience. Soon after the completion of that picture book, Chihiro was diagnosed with liver cancer, and after seeing her son get married from her hospital room, she passed away in 1974, at the early age of 55.