On 12 October 1960, , chairman of the Japan Socialist Party, was assassinated at Hibiya Public Hall in Tokyo. During a televised debate, 17-year-old right-wing ultranationalist Otoya Yamaguchi charged onto the stage and fatally stabbed Asanuma with a wakizashi, a type of traditional short sword. Yamaguchi committed suicide while in custody.
The assassination weakened the Japan Socialist Party, inspired a series of copycat crimes, and made Yamaguchi an enduring hero and subsequently a martyr to the Greater Japan Patriotic Party and other Japanese far-right groups.
Background
In 1959, Asanuma, a charismatic figure on the Japanese Left, had caused controversy in Japan by visiting Communist China and declaring the United States "the shared enemy of China and Japan" during a speech in Beijing. After returning to Japan, Asanuma, in his role as leader of the , became one of the key leaders and main public faces of the massive Anpo protests, a series of protests against the 1960 revision of the U.S.-Japan Security Treaty (known as "Anpo" in Japanese).
Asanuma and the JSP led a number of mass marches on the Japanese National Diet. Notably, as referenced in Yamaguchi's writings, was the June 15th incident, where on 15 June 1960, anti-treaty protestors stormed the National Diet compound, eventually forcing their way in through the south gate of the chamber. This led to a brawl with counter-protestors, resulting in severe injuries.
Right-wing groups and individuals, such as Bin Akao and his , were doubly upset with Asanuma for portraying the U.S. as Japan's main enemy on his trip to China and for actively opposing the Security Treaty. The massive left-wing protests made Akao, his party and many other right-wing groups convinced that Japan was on the verge of a communist revolution.
The aforementioned began staging and participating in protests, counter protests, and other political activities. Akao gave numerous public speeches, of note mentioning the importance of the youth's role in resisting their political rivals. One of these speeches attracted the attention of Otoya Yamaguchi, who would resultingly join the party, participate in their activities, and later assassinate Asanuma.
The perpetrator
Yamaguchi was born on 22 February 1943 in Yanaka, Taitō ward, Tokyo, the son of a high-ranking officer in the Imperial Japanese Army. Beginning in early childhood, Yamaguchi began reading newspapers. Angered by what he read, he became vehemently critical of politicians and later interested in nationalist movements. Through his older brother's influence, he began attending speeches and participating in right-wing protests and counter-protests. At age 16, he formally joined Bin Akao's ultranationalist Greater Japan Patriotic Party.
Yamaguchi participated in the Anpo counter-protests, and was arrested and released 10 times over the course of 1959 and 1960.
Over the course of the Anpo protests, Yamaguchi became further disillusioned with Akao's leadership, and later resigned from the party. In his testimony given to police, he stated that he resigned from Akao's party in order to "lay [his] hands on a weapon" and be free to take more "decisive action."
Assassination
On October 12, 1960, Asanuma was participating in a televised election debate at Hibiya Public Hall in central Tokyo, featuring the leaders of the three major political parties. Also scheduled to participate were Suehiro Nishio of the Democratic Socialist Party and prime minister Hayato Ikeda of the ruling Liberal Democratic Party. The debate was sponsored by the Japanese Elections Commission, the Alliance for Clean Elections and national broadcaster NHK, which was also televising the event. There was also an audience of 2,500 people in the hall.
Nishio spoke first, and at 3:00 p.m., Asanuma advanced to the podium and began his speech. Immediately, right-wing groups in the audience began loudly heckling him, and the television microphones and reporters sitting in the front row could not hear him, forcing the NHK moderator to interrupt and call for calm. At 3:05 p.m., as the audience finally calmed down and Asanuma resumed speaking, Yamaguchi rushed onto the stage and made a deep thrust into Asanuma's left flank with a samurai short sword (wakizashi) that he had stolen from his father. Yamaguchi then tried to turn the sword on himself but was swarmed and detained by bystanders.
At the time of the murder, Yamaguchi had a note in his pocket that read: