Haw. Rev. Stat. § 658A-6: Validity of agreement to arbitrate.

(a) An agreement contained in a record to submit to arbitration any existing or subsequent controversy arising between the parties to the agreement is valid, enforceable, and irrevocable except upon a ground that exists at law or in equity for the revocation of a contract.

(b) The court shall decide whether an agreement to arbitrate exists or a controversy is subject to an agreement to arbitrate.

(c) An arbitrator shall decide whether a condition precedent to arbitrability has been fulfilled and whether a contract containing a valid agreement to arbitrate is enforceable.

(d) If a party to a judicial proceeding challenges the existence of, or claims that a controversy is not subject to, an agreement to arbitrate, the arbitration proceeding may continue pending final resolution of the issue by the court, unless the court otherwise orders.