As I reported before, there are discussions about the referendum for Constitutional recognition of local government, altering section 96 of the Australian Constitution.
As it happens, there are also discussions whether section 96 of the Constitution of Japan should be altered or not. Section 96 of the Japanese Constitution states that amendments shall be initiated by the Diet (Parliament), through a concurring vote of two-thirds or more of all the members of each House and shall thereupon be submitted to the people for ratification, which shall require a yes vote of a majority of all votes cast.
The Japanese Constitution is categorised as relatively solid compared with those of other countries. We have never experienced attempts to alter the Constitution. On the other hand, in Australia, there have been 44 attempts to amend the Constitution, of which eight have been successful.
From a Japanese perspective, it is interesting that a double majority (a majority of states and a majority of voters) is required in Australia for electors to approve altering of the Constitution.
The difference in Constitutional amendment processes shows the basic difference in national structure between a unitary and federal system.