Tokyo subway sarin attack — Asahara arrested, 16 May · 87

On 20 March 1995 members of Aum Shinrikyo released sarin on Tokyo subway trains, killing 13 people; the investigation and trials remade Japanese security law. On the morning of 20 March 1995, members of the new religious movement Aum Shinrikyo released the nerve agent sarin on five Tokyo subway trains converging on the Kasumigaseki government district. Tokyo Metropolitan Police later treated 13 deaths as official after a 2008 compensation survey added one fatality to the first count of 12; a 14th death was recorded in 2020. Several thousand people sought treatment — figures of about 5,500 to 6,300 appear in police and later surveys. This page does not describe injuries or how the agent was made or released.

The attack was a criminal and terrorism investigation, not a war. Police had already been moving toward Aum after the June 1994 Matsumoto sarin case (eight dead) and earlier crimes, including the 1989 murder of lawyer Tsutsumi Sakamoto and his family. Asahara Shoko, born Matsumoto Chizuo, was arrested on 16 May 1995. He was sentenced to death in 2004; the sentence became final in 2006. He and other Aum convicts were executed beginning on 6 July 2018.

Legal aftermath included revocation of Aum’s religious-corporation status, a 1995 revision of the Religious Corporations Act, and the 1999 Act on the Control of Organizations Which Have Committed Acts of Indiscriminate Mass Murder. Successor groups remain under public-security watch. English-language memory framed Aum as a “doomsday cult” that ended Japan’s reputation for public safety.