The palace, named Keoua Hale, was sold to the government to be used for educational purposes.

Plans for a new building were commissioned to accommodate the rapid growth of students going on to secondary schools during the booming 1920s.

The original design of the school was drawn up in 1922 by the prominent architectural firm of Walter Emory and Marshall Webb, who also designed such notable buildings as the grand Tudor Revival residence of Charles M. Cooke Jr. (1912), the eclectic Indian-Western-style Honpa Hongwanji Hawaii Betsuin Buddhist Temple (1918), and the Neoclassical Revival and Art Deco Hawaii Theatre (1921).

This style was further enhanced by the Territorial building inspector at the time, Harry K. Stewart, a graduate of Central Grammar School who went on to design many other public buildings in the Territory, such as Baldwin High School and Molokai Public Library.

Passantino was credited for doubling math scores and increasing English preparedness by 50%.