Miyake dropped out of school as a teenager and began working, first on the sugar plantation, then for Waimea Garage and Electric Company.
After his discharge from the military, he bough Waimea Garage and Electric Company from William Olin Cromwell and became its president.
[1] When World War II started, Miyake chose not to run for a sixth term and instead volunteered for the Army, where he worked for the Office of Civilian Defense.
[1] In 1948, after World War II, Miyake was elected to a seat in the Hawaii Territorial House of Representatives.
In 1952 he was elected to the Hawaii Territorial Senate, where he lobbied for the establishment of Kauai Community College.