Haw. Rev. Stat. § 711-1104: Unlawful assembly.

(1) A person commits the offense of unlawful assembly if:

(a) The person assembles with five or more other persons with intent to engage in conduct constituting a riot; or

(b) Being present at an assembly that either has or develops a purpose to engage in conduct constituting a riot, the person remains there with intent to advance that purpose.

(2) Unlawful assembly is a misdemeanor. [L 1972, c 9, pt of §1]

COMMENTARY ON §711-1104

Section 711-1104 is intended to reach those who have assembled for the purpose of rioting or who are on their way to the scene of a riot, but who have not yet begun to riot, or who associate with a group of known potential rioters with intent to aid their cause. It thus comprises both unlawful assembly and riot at the common law, and constitutes in effect an expanded concept of attempted riot. Punishment is at the misdemeanor level.

Specifically the section requires assembling with five or more others with intent to engage in conduct constituting a riot, or remaining at an assembly that develops a purpose to engage in a riot, with intent to advance that purpose.