Former activists petitioning for a retrial after they were fined for unlawfully entering a U.S. military base in Tokyo nearly 60 years ago have found their case in the spotlight once again due to the Abe administration's push for Japan to have the right to exercise collective self-defense.

The new security legislation permitting collective self-defense took effect in March and the opposition bloc is campaigning on the issue in the lead-up to the July 10 Upper House election.

The Supreme Court decision in the Sunagawa Case, named after the area of Tokyo where the U.S. base was located, was issued in December 1959. It overturned the initial ruling by the Tokyo District Court, which acquitted all seven defendants accused of violating the special criminal law under the Japan-U.S. security treaty.