In September 1931 Puyi sent a letter to Jirō Minami, the Japanese Minister of War, expressing his desire to be restored to the throne. On the night of 18 September 1931, the Mukden Incident began when the Japanese Kwantung Army blew up a section of railroad belonging to the Japanese-owned South Manchurian Railroad company and blamed the warlord Marshal Zhang Xueliang. On this pretext the Kwantung Army began a general offensive with the aim of conquering all of Manchuria. Puyi was visited by Kenji Doihara, head of the espionage office of the Japanese Kwantung Army, who proposed establishing Puyi as head of a Manchurian state.