HRS §381-12
No forced work
This section says the law cannot force you to work against your will. You may quit your job without it being illegal. It only covers this one point about voluntary work.
employees
The statute, as written — Employee need not work involuntarily
Nothing in this chapter shall be construed to require an individual employee to render labor or service without the individual employee's consent, nor shall anything in this chapter be construed to make the quitting of the individual employee's labor or service by an individual employee an illegal act.
LawTrove is not legal advice. The summary above is a computer-generated restatement — the authoritative text is the official version linked above.