It doesn't hurt to ask, of course.
But also, I know other airlines have a policy where they will seat you at least in pairs of 2 if everyone is on the same booking. In your case, they would sit 2 together and 3 together. I have no idea if Hawaiian has this policy, but it doesn't hurt to ask at the checkin counter.
This should hold some relevance:
http://help.hawaiianair.com/app/answ...id/419/kw/seat
Seat Assignments
Pre-reserved seats are limited by differences in aircraft seating configurations and seats with qualifications such as emergency exit rows. The common seats alike on all aircraft are the seats offered for pre-assignment.
Within 24 hours of departure, additional seats become available when the actual aircraft is assigned to a specific flight and the seat configuration is finalized. Pre-assigned seat availability should not be confused with your confirmation of a seat aboard the flight.
Hawaiian Airlines will do all possible to provide passengers with their preferred seating. Upon check-in at the airport, it is also our policy to make every attempt to seat children under the age of 12 with an accompanying adult. Prior to check-in, neither Reservations nor Web Support can guarantee seats together.