There has been a new development in a lawsuit filed by a group of citizens calling on the government to disclose diplomatic documents related to the 1972 reversion of Okinawa from U.S. to Japanese rule. One of the documents concerns an alleged secret financial concession to Washington — a payment by Tokyo of $4 million to help fund the conversion of U.S. military areas back to farmland.

The Tokyo District Court on Aug. 25 accepted the plaintiffs' request that the court let Mr. Bunroku Yoshino, former director general of the Foreign Ministry's American Bureau, testify as a witness. Mr. Yoshino, who was in charge of reversion negotiations, will appear before the court Dec. 1.

Having obtained a photocopy of a June 1971 note with the initials "BY" from the U.S. National Archives, the plaintiffs submitted it to the court as evidence. It mentions a $4 million secret payment. The plaintiffs think that the same note exists in Japan and demands that the state disclose it and any related documents. The state insists that no secret pact was made during the Okinawa reversion negotiations.