On December 27, 1923, a young man named Daisuke Nanba stood at the Toranomon intersection in downtown Tokyo, waiting for a carriage. Three months earlier, the Great Kanto earthquake had reduced much of the capital to rubble. In the chaos that followed, vigilante mobs had massacred thousands of Korean residents and Japanese leftists. Nanba, the son of a Diet member, carried a small pistol. When the carriage of Crown Prince and Regent Hirohito rolled past on its way to the opening of the 48th Session of the Imperial Diet, Nanba fired. The bullet shattered a window, wounded a chamberlain, and missed Hirohito entirely. The shot lasted a fraction of a second. Its political aftershocks reshaped Japan for a generation.
The Toranomon intersection sits between the Akasaka Palace and the National Diet building in the heart of Tokyo's government district. In December 1923, the city was still reeling from the September earthquake that had killed over 100,000 people. Amid the disaster, the Kanto Massacre had claimed the lives of thousands of Koreans and Japanese leftists, killed by vigilante groups and, in some cases, by police and military units. Daisuke Nanba, a 24-year-old communist, was consumed by fury at these killings and by the 1910 execution of the anarchist Shusui Kotoku, convicted in the High Treason Incident for an alleged plot against Emperor Meiji. For Nanba, the regent's carriage represented a system that crushed dissent and slaughtered the vulnerable. His weapon was small. His rage was not.
Nanba fired from close range as the imperial carriage passed. The bullet pierced a window and struck a chamberlain riding alongside Hirohito. The regent himself was unharmed. Nanba was seized immediately. In custody, he maintained that he was rational and that his actions were deliberate -- a political act, not the outburst of a madman. The court records agreed with his claim of sanity. But the authorities had no use for a rational assassin. Nanba was publicly declared insane, tried, sentenced to death on November 13, 1924, and executed two days later. The speed of the proceedings and the gap between the official psychiatric assessment and the public narrative revealed how deeply the incident had unsettled the Japanese government.
Prime Minister Yamamoto Gonnohyoe, a former admiral who had already served once as premier, took personal responsibility for the security failure. He resigned, along with his entire cabinet and a number of senior officials. His successor was Kiyoura Keigo, a deeply conservative figure who formed a cabinet drawn exclusively from the House of Peers -- Japan's unelected upper chamber -- with no ties to any political party. The shift was dramatic. Yamamoto had led a relatively moderate government. Kiyoura's appointment signaled that the attempted assassination had given Japan's conservative establishment the leverage it needed to consolidate power and marginalize the political parties that had been gaining influence during the Taisho democracy period.
The Toranomon Incident did not end with Nanba's execution or Yamamoto's resignation. The government cited it as one of the justifications for the Peace Preservation Law of 1925, one of the most consequential pieces of legislation in prewar Japanese history. The law criminalized any attempt to alter the kokutai -- the national polity centered on the emperor -- and targeted communist, socialist, and anarchist organizations. Under its provisions, thousands of political dissidents were arrested, imprisoned, and in some cases tortured throughout the late 1920s and 1930s. A single bullet that missed its target had provided the pretext for a systematic crackdown on political opposition that lasted until Japan's defeat in 1945. The Toranomon intersection, now surrounded by gleaming office towers and the Toranomon Hills development, carries no memorial to what happened there. The history lives only in the record.
Located at 35.671N, 139.749E in the Toranomon area of Minato ward, central Tokyo. The intersection sits between the Akasaka Palace (State Guest House) to the northwest and the National Diet Building to the east, both visible as large structures with distinctive rooflines amid the dense urban landscape. The modern Toranomon Hills tower complex now dominates the immediate area. Nearest airports: Tokyo Haneda (RJTT) approximately 8 nm south, Narita International (RJAA) approximately 37 nm east. Best viewed at 2,000-4,000 feet AGL. The wide Sotobori-dori avenue running through Toranomon serves as a visual landmark.