This study sets forth the post-1945 development and present status of Japanese constitutional and procedural law on court-mass media relations, while analyzing aspects of the interaction between law and sociopolitical thought and behavior. A recent and dramatic illustration of the issues is provided by the Hakata Station Film Case: A Fukuoka court's subpoena (August 29, 1969) for newsfilm taken during a student-police encounter occasioned conflict between Japan's mass media and courts; the dispute was resolved by a film seizure (March 4, 1970) three months after the Supreme Court had upheld the subpoena's constitutionality. The media maintain that Article 21 of the Constitution (freedom of expression) gives them the right to determine when their used or unused television film or still photographs may be employed as court evidence, even in the absence of privileged communications. This and other court cases considered, arising from Japan's perennial demonstrations, illustrate a strong tendency toward in-group unanimity, new problems in news and evidence gathering, and the operation of a non-Western legal system influenced by Japanese, European, and American traditions.