Yasunari Kawabata had Parkinson's disease), a possible illicit love affair, or the shock caused by the suicide of his friend Yukio Mishima in 1970. Unlike Mishima, Kawabata left no note, and since (again unlike Mishima) he had not discussed significantly in his writings the topic of taking his own life, his motives remain unclear. However, his Japanese biographer, Takeo Okuno, has related how he had nightmares about Mishima for two or three hundred nights in a row, and was incessantly haunted by the specter of Mishima. In a persistently depressed state of mind, he would tell friends during his last years that
China–Japan relations of Taipei with Japan in 1952. Similarly, when Japan normalized its relations with the PRC in 1972, Mao Zedong waived the claim of war reparations from Japan. Ex-Japanese Prime Minister Hatoyama Yukio offered personal apology for Japan's wartime crimes, especially the Nanking Massacre, "As a Japanese citizen, I feel that it's my duty to apologise for even just one Chinese civilian killed brutally by Japanese soldiers and that such action cannot be excused by saying that it occurred during war." The Japan–Taiwan official split is one of the fundamental principles of Sino-Japanese relations. The PRC emphasises Taiwan is a part