Wakatsuki was born on August 17, 1929 in Kalihi, a district of Honolulu, Hawaii to immigrants from Japan.
After leaving the army, Wakatsuki finished his degree at Bowling Green University.
By 1975 he was the Speaker of the House and had gained the nickname "The Opihi" because once he took a position, he would not budge, much like the difficult to move mollusk.
He retired from politics in 1980 after being appointed the Hawaii State Circuit Court judge by George Ariyoshi.
Prosecutor Charles Marsland criticized Wakatsuki's legal and political experience, but he was confirmed by the Senate and joined the Supreme Court on September 7, 1983.