While debate continues on whether to amend the nation's pacifist Constitution, less attention has been given to the referendum system under which the public will give its final say.
If such a vote is held, it will be Japan's first-ever national plebiscite on any topic. But critics say that without addressing at least some of what they see as flaws in the constitutional referendum law, the historic event could leave a bitter aftertaste.
One contentious point of the law is whether it ensures a level playing field in the use of political advertising ahead of the referendum, with the only notable regulation being a ban on paid TV and radio ads for two weeks prior to the vote.