[2] Iwamatsu was born September 21, 1908, in Nejime, Kimotsuki District, Kagoshima, and raised there on the southern coast of Kyushu.
[4][5] He then joined a group of progressive artists, sympathetic to the struggles of ordinary workers and opposed to the rise of Japanese militarism.
It was then that he first used the pseudonym Taro Yashima, out of fear that there would be repercussions for Mako and other family members if the Japanese government knew of his employment.
The New Sun, published in 1943 under the name Taro Yashima, was a 310-page autobiographical picture book for adults about life in pre-war statist Shōwa Japan, including details of the harsh and inhumane treatment he and his wife underwent for participation in anti-militarist groups in the 1930s.
The 276-page book continues the story of his life in Japan under military rule, this time with added Japanese text.
[6][5] During one passage, he mourns the loss of his esteemed teacher "Mr. Isobe", who had been killed in action after being drafted into military service.
[9] Yashima returned to his home village of Nejime, visiting childhood classmates and familiar scenes that he depicted in several of his children's picture books.