Totally realistic. It's a ten hour flight with a six hour time difference, so you'll want to have a decent amount of time when you get there. Allow a couple of days to get over jetlag just chilling in a hotel by the beach.
I personally love Waikiki (some folks like the other islands) -- I'd do two days in Waikiki, then a couple of days on the Big Island to see the volcano, then a few more days in Waikiki. Hike up to Manoa Falls, go see Diamond Head, eat plate lunch, take the bus trip to the North Shore and stop for shave ice.
I'm coming with.
