Haw. Rev. Stat. § 481-7
The payment or allowance of rebates, refunds, commissions, or unearned discounts whether in the form of money or otherwise or extending to certain purchasers, special services, or privileges not extended to all purchasers purchasing upon like terms and conditions, to the injury of a competitor and where the payment or allowance tends to destroy competition, is an unfair practice and any person, firm, or corporation resorting to such trade practice shall be subject to injunction or suit for damages as provided in this chapter; provided that this section shall not apply to dealings between a principal and agent under the terms of a bona fide agency contract, nor to sales by an employer to the employer's bona fide employees of any articles which are part of the stock.
HRS § 481-7