Haw. Rev. Stat. § 551G-31

If a guardian has been appointed in another state and a petition for the appointment of a guardian is not pending in the State of Hawaii, the guardian appointed in the other state, after giving notice to the appointing court of an intent to register, may register the guardianship order in the State of Hawaii by filing as a foreign judgment in a court, in any appropriate judicial circuit of the State of Hawaii, certified copies of the order and letters of office.