In 1882, he traveled to Tokyo as Envoy Extraordinary and Minister Plenipotentiary to the Court of Japan to negotiate Japanese immigration to Hawaii.

Born on October 2, 1843, at Lāhainā, on the island of Maui, Kapena was the son of Mākini and High Chiefess Nāʻawa, a relative of the Kalākaua family.

He was adopted under the Hawaiian custom of hānai by his uncle Jonah Kapena, an influential statesman, judge and royal advisor since the reign of King Kamehameha III (r.

[1] During the reign of Kamehameha V (r. 1864–1872), he was commissioned on January 16, 1864, as first lieutenant of the 1st Company of the Yeomanry, a volunteer army regiment in the military of Hawaii.

[14] He was made a colonel on the king's personal military staff on January 27, and judge of the first circuit court on the island of Oahu, serving in the latter position from April 1, 1873, to July 13, 1874.

[13][15] In July 1873, King Lunalilo and his foreign minister Charles Reed Bishop considered a proposal to cede Pearl Harbor to the United States in exchange for a reciprocity treaty.

[15][21][22][23] On January 10, 1876, Kapena was appointed by the king to be an official member of the House of Nobles, the upper chamber of the legislature.

He served as the finance minister from December 5, 1876, until Kalākaua demanded the resignation of his entire cabinet in the middle of the night on July 1, 1878.

It was widely suspected that Kalākaua's sudden replacement of his cabinet was influenced by American businessman Claus Spreckels, who had refinanced the King's debts the night before in order to secure water rights for his sugarcane plantation on Maui.

[15][29] When the king chose a new cabinet in 1880, Kapena was replaced in the position by the Italian adventurer Celso Caesar Moreno to the vehement opposition of the diplomatic corps and political leaders in Honolulu.

[30] Kapena later returned to another cabinet headed by Walter Murray Gibson when he was appointed Minister of Finance for a second term in February 1883 after Kaʻai was removed for "dereliction of ministerial duty.

Along with his secretary John Lot Kaulukoʻu, he traveled to Japan to negotiate the prospect of Japanese immigration to the Hawaiian Islands.

[40][41][42] Kapena's funeral at St. Andrew's Cathedral the following day was attended by the King, members of the royal family, ranking members of the government and Honolulu society, Viscount Torii and T. Fujita of the Japanese legation, the Lodge Le Progres de L'Oceanie and the Hawaiian Lodge No.

After the service, a funeral procession brought the hearse carrying his casket to Kawaiahaʻo Church where he was buried with Masonic rites.