[5] During production, she became pregnant, and after a doctor advised against working during her pregnancy, she took an eight-episode break from the role with Kazue Tagami [ja] as her substitute, resulting in several children complaining to the show's broadcasting network, Fuji TV.
[9][8] Tezuka originally wanted Atom's voice actress to remain unchanged,[10] and Shimizu reprised her role as Astro Boy in the show's 1980 colour remake and in the 2000 film The Last Mystery of the 20th Century.
[12] In 1968, Shimizu starred in Humanoid Monster Bem as Belo,[11] a character she later recalled struggling with by having to convey "a dark image because he was a child crawling under the ground".
[9] Other characters Shimizu voiced include Mame-tan in Detective Brat Pack, Kanbō in Sabu to Ichi Torimono Hikae, Tomiko Shimamoto in Attack No.
1, Ken in Hitori Bocchi, Inspy in Marine Boy, Tetsuji in Ikkyū-san, Gorō Makino in Uchu Enban Daisenso, Mirun in Gaiking, Kira in Galaxy Express 999, Yusuf in Animation Kikō: Marco Polo no Bōken, Patty in Triton of the Sea, Adam in Undersea Super Train: Marine Express, Prince Alor in Beast King GoLion, Peko in Doraemon: Nobita and the Haunts of Evil, Tezuka's mother in The Tezuka Osamu Story: I Am Son-goku, and Ricky in the 2004–2006 anime adaptation of Black Jack.
[11] Shimizu wanted to focus on Shinjinkai after Astro Boy's final episode, but she had a child while the series was still airing, making it difficult to participate in stage acting, and moved to the same office as Nobuyo Oyama, her friend from the Haiyuza school.