It is most likely that you (or your predecessors in title) have created an easement by prescription. The case of EDITH T. TANAKA v. SPENCER SUETOSHI MITSUNAGA, KIMIYO MITSUNAGA AND YACHIYO MITSUNAGA, 43 Haw. 119, (Hi., 1959) defines this kind of easement:
An easement by prescription is created by a use of the claimed easement area adverse to the owner of the land for the period of prescription. In this jurisdiction the prescriptive period is 10 years. Generally, the adverse character of the use necessary to establish an easement by prescription is the same as that which is necessary to establish title by adverse possession. It must be continuous, open, and notorious. A person who claims an easement in adjoining land by prescription, as appurtenant to his land, need not show continued use by himself for the prescriptive period but may tack the use by his predecessors in title.
You may also have an easement by necessity. This is an easement that requires proof of unity of title between the dominant and servient estates, followed by a severance thereof. In general terms, you have to prove that you and your neighbor's property were once one tract and they were severed, thereby landlocking your property. This is a less likely easement based on the facts provided. But, it is another possibility. See AUGUST K. DUVAUCHELLE v. KAKANI, 2001 Haw. App. LEXIS 139 (2001).
I suggest that you have a local attorney take a look at the real property registry to define your exact property lines and whether any easements are on file. If not, the next step would be to file suit to determine whether you have an easement.
Good luck and feel free to ask any follow-ups.