He was born on Maui in the district of Waiehu, attending both Lahainaluna High School and the Mid-Pacific Institute in Honolulu.

Affiliated with the Hawaii Mission Board, Kamau was also a judge who served as a district magistrate at Puna at the same time he pastored a church at Opihikao.

Kamau had an affiliation with Haili Church in Hilo, and along with other ministers in the islands, sometimes participated in larger events with Kawaiahao.

[5] Kamau was 83 years old when he accepted the position, the same age Henry Hodges Parker had been when he retired from his ministry at Kawaiahao.

When Kahale was promoted to Kahu in 1940, Kamau was put on retirement as pastor emeritus allowing him to continue as a practicing minister without the responsibilities of administration.