Haw. Rev. Stat. § 551-35: Natural guardian and conservator of person alleged to be incapacitated or in need of protective proceedings.

The father and mother of an incapacitated or protected person are jointly and severally the person's natural guardians and conservators. They shall have equal powers and duties with respect to the person and neither shall have any right superior to that of the other concerning the person's custody or control or any other matter affecting the person; provided that if either parent dies or abandons the family or is incapable for any reason to act as guardian or conservator, or both, the guardianship or conservatorship, or both, devolves or devolve upon the other parent, and that when the parents live apart, the court may award the guardianship or conservatorship to either of them, having special regard to the interests of the incompetent adult person.