A hole in the wall, great if you're eating on a budget but not wanting to sacrifice quality. It's walkable from Waikiki Beach, just behind the Hyatt, on Koa Ave, just parallel to the main street that is Kalakaua Ave. They make their musubi on the spot so it comes out warm and fresh. The rice is light and quite fluffy- not too sticky nor dry. The filling is sufficient, unlike other places where the rice to other ingredient ratio is too high! Regular spam musubi is $1.88 before tax, with other varieties up to $2.38. I LOVED LOVED LOVED the spicy salmon with cod roe... It was spicy but manageable! They also have bento lunches with various combinations of Japanese food- fried chicken, salmon, daikon... each for about $5 to $7. I got a deluxe combo- 2 musubis (pick any!), fried chicken, 2 small sausages, and a lovely bowl of Japanese vegetable stew (not just miso, but with a good serving of daikon and carrots!)
2 tiny tables inside and an equally small one outside... so if you don't have a seat, take your fresh musubi and enjoy it as you sit by the beach which is a 5 min walk away, to the envy of everyone eating cold sandwiches and much more expensive but regular fare!
I went there thrice in 2 days, but could only get ONE musubi with the cash I had left. They take visa and mastercard too, but not amex!