A revision of the Japan copyright law went into effect Dec. 30 after the bill was passed through the country's National Diet (legislature) on June 29, 2018. It extended the copyright protection period from 50 years to 70 years after the author's death.
The extension was first discussed as part of the Trans-Pacific Partnership (TPP), which seemed dead after U.S. President Donald Trump withdrew his country from the negotiations. But the remaining 11 countries, which include Japan, have moved forward with the TPP, including the copyright protection change.
The revised copyright law in Japan was timed to coincide the TPP going into effect, but the law is not conditional on the trade partnership.
Intellectual property in Japan that has entered the public domain within the last 20 years may be returned to copyright control, contingent on when the author died.
The Japanese law has a peculiar provision which allows anyone with an interest in an intellectual property, not just the rights holders, to sue a party it deems has committed copyright violation. Thus the Japanese administering society for musical compositions, the Japanese Society for Rights of Authors, Composers and Publishers (JASRAC), will apparently be able to sue anyone for using a composition without a contract in place even if the composer has granted permission for use.
Whether this situation will come to pass is unknown but the revised law appears to sanction it.