Is Hawaiian similar to japanese?
I have known that there are a couple of things similar in japan and hawaii but does the language have anything in common?
They are not (closely) related, if that's what you're asking. There are some suggestions that give Japanese a distant relationship with the Austronesian languages, but it would almost certainly be too distant to be of any real use when learning the languages, if it exists.
There is some cultural exchange between the two places and some words have been borrowed from each language to the other. In addition, they both have very similar syllable structures and quite a bit of overlap in sound inventory. However, the grammar is very different and most of the vocabularies have little relationship. Speaking one language will not really help you at all with the other.