Pupuakea is said to be a son of Keawenui-a-Umi, mother unknown. As younger brother of Lonoikamakahiki, he was appointed Alii-ai-moku of Ka'u, after the defeat of all the rebel district chiefs by Keawenui-a-Umi. He was the only chief who stood by Lonoikamakahiki when it was incorrectly thought that he had murdered his wife and co-regent Kaikilani (daughter of Kuka'ilani).