It was the title match of the decade: the rumble in the academic jungle. On May 13, 1969, literary titan Yukio Mishima strutted onstage in front of a 1,000-strong audience at the University of Tokyo to debate with representatives of the All Campus Joint Struggle Committee, otherwise known as Zenkyoto.

The event has since acquired legendary status, and was filmed by broadcaster TBS, though the footage had long been thought lost. Recently discovered and restored, this riveting document forms the heart of Keisuke Toyoshima’s “Mishima: The Last Debate.”

The showdown took place at the peak of the student protest movement, during the so-called “seiji no kisetsu” (“season of politics”). The documentary opens with images of pitched battles in the streets of Tokyo, the sheer intensity of which still shocks today.