Haw. Rev. Stat. § 557A-402

Subject to the terms of a recipient trust, an amount received as a distribution of income from a trust or an estate in which the trust has an interest other than a purchased interest shall be allocated to income. An amount received as a distribution of principal from such a trust or estate shall be allocated to principal. If a trustee purchases an interest in a trust that is an investment entity, or a decedent or donor transfers an interest in such a trust to a trustee, section 557A-401 or 557A-415 shall apply to a receipt from the trust.