Otoya Yamaguchi (22 February 1943 – 2 November 1960) was a Japanese ultranationalist youth who infamously assassinated socialist politician Inejiro Asanuma with a wakizashi short sword during a televised political debate on 12 October 1960. He was arrested for Asanuma's murder and hanged himself in police custody on 2 November.
Otoya Yamaguchi was born in the Taito ward of Tokyo, Japan on 22 February 1943, and he joined the ultranationalist Greater Japan Patriotic Party at the age of 16 due to his staunch anti-communism and support for the United States. After a 1960 revision of the US-Japan Security Treaty led to the Japan Socialist Party staging protests against the government, Yamaguchi was convinced that a communist revolution was inevitable, and he mobilized fellow far-right nationalists to stage counter-protests. He soon came to see party leader Bin Akao as insufficiently radical, so he left the Greater Japan Patriotic Party. On 12 October 1960, at 3:05 PM, he rushed the stage of the Hibiya Public Hall in Tokyo as socialist leader Inejiro Asanuma debated his Jiminto opponent, and he ran Asanuma through with a wakizashi short sword he had stolen from his father. Before he could commit seppuku, Yamaguchi was swarmed and detained by bystanders, and he was promptly arrested by police. He told the police that he had acted alone and without the direction of others, and, on 2 November 1960, he used a mixture of toothpaste and water to write on his cell wall, "Long live the Emperor" and "Would that I had seven lives to give for my country." He then knotted his bedsheet into a makeshift rope and hanged himself from a light fixture. He was hailed as a martyr by the Japanese right-wing, and his assassination of Asanuma inspired numerous copycat incidents targeting prominent leftist politicians and societal leaders.