Haw. Const. art. VI, § 2

The supreme court shall consist of a chief justice and four associate justices. The chief justice may assign a judge or judges of the intermediate appellate court or a circuit court to serve temporarily on the supreme court, a judge of the circuit court to serve temporarily on the intermediate appellate court and a judge of the district court to serve temporarily on the circuit court. As provided by law, at the request of the chief justice, retired justices of the supreme court also may serve temporarily on the supreme court, and retired judges of the intermediate appellate court, the circuit courts, the district courts and the district family courts may serve temporarily on the intermediate appellate court, on any circuit court, on any district court and on any district family court, respectively. In case of a vacancy in the office of chief justice, or if the chief justice is ill, absent or otherwise unable to serve, an associate justice designated in accordance with the rules of the supreme court shall serve temporarily in place of the chief justice.