As Japan lost the Second World War in 1945, Nichitsu and its zaibatsu collapsed and was forced to abandon all properties and interests in Korea. Furthermore, the US-controlled Allied occupation of Japan ordered the dismissal of the company, regarding it as a company that adhered to the militarism government. In 1950, the , usually referred to as Shin Nichitsu, was founded as a successor of the old company. Other successor companies include Asahi Kasei and Sekisui Chemical. Minamata disease Nichitsu had started production of acetaldehyde using a mercury catalyst at its Minamata plant in May 1932, and Shin Nichitsu continued production after the war. The plant discharged wastewater from its acetaldehyde plant into Minamata Bay via Hyakken Harbour. The wastewater contained many pollutants and poisonous substances including methylmercury, a highly toxic chemical. This chemical was absorbed by fish and shellfish and bioaccumulated up the food chain. People who unknowingly ate the fish over many years suffered from severe mercury poisoning. Hajime Hosokawa, a doctor at a Shin Nichitsu's company hospital, officially reported on May 1, 1956 an "epidemic of an unknown disease of the central nervous system", marking the official discovery of Minamata disease. In 1963, doctors at Kumamoto University concluded that the cause of Minamata disease was mercury emitted by Shin Nihon Chisso Hiryo. In 1965, the company changed its name to . In May 1968, Chisso finally stopped using a mercury catalyst in the production of acetaldehyde. In 1969, patients sued Chisso for compensation. Many lawsuits were filed against Chisso after 1969, and some of them go on even now. Chisso president, later chairman Yutaka Egashira (later maternal grandfather of Masako, Empress of Japan) used yakuza in order to threaten and silence patients and their supporters. Patients and their supporters started the "single shareholder" movement by buying one share of Chisso each, which was aimed at accusing the executives of Chisso in its general meeting. A thousand of the single shareholders participating in the movement gathered in front of a hall in Osaka to attend the general meeting called on November 28, 1970, but the company prevented them from entering the hall by asking yakuza to become shareholders and occupy the hall. The meeting ended in five minutes with all the bills submitted by the board approved. In addition, Chisso had American photographer and photo-journalist W. Eugene Smith beaten by yakuza goons after Smith published a highly regarded