The mortgage shall operate only as a contract between the parties with respect to, and shall not create a lien upon real property or fixtures acquired in any manner by the mortgagor subsequent to the execution of the mortgage, if there are not described therein such real property, such fixtures and the real property to which such fixtures are or will be affixed, unless and until the mortgagor or the mortgagee, at the time of or subsequent to the acquisition, executes and duly records in the bureau of conveyances an instrument or affidavit containing a reference to the book and page or document number where the mortgage is recorded and also a description of such real property, such fixtures and the real property to which such fixtures are or will be affixed sufficient to identify and locate the same, which description of real property may be made by describing the deed or other instrument of conveyance by which the real property was acquired or by describing the land by metes and bounds.
HRS § 506-3