Toshiko Mayeda was born in Tacoma, Washington. She grew up in Yokkaichi, Mie, and Osaka. When the United States entered World War II after the Japanese attack on Pearl Harbor, she and her father Matsusaburo Kuki were sent to the Tule Lake War Relocation Center. Whilst there she met her future husband, Harry Mayeda. After the war, she graduated with a bachelor's degree in chemistry from the University of Chicago in 1949.