Unless there is an actual cafe out there called this specifically, I don't see much hope for it. From what I've seen, Waikiki is a neighbourhood in Hawaii. Also Googled and found a brand of this in Spain...that's about it. They have contact details, no site...probably don't care. If expanded to "Hawaii Cafe", you'd be on the right end of it. Just struggle with yours, as an individual neighbourhood, with words in reverse. Hard sell, IMO