Japan History Lab

A Year of High Treason, 1910-1911

by Kate Riordon

Introduction and Background

The High Treason Incident was so called because those accused and condemned for it threatened not only the life of the Meiji Emperor, but also the symbol of divinity he embodied and the social order that hinged on that image. It was their belief that the Emperor was not a god, but rather a mortal man like the rest of them. The series of events that then took place from the spring of 1910 to the early months of 1911 were rather small in the grand scheme of national and international affairs, but they none the less resounded around the world as acts of oppression, tyranny, and injustice. Within the borders of the Japanese homeland the ramifications of the assassination plot saw little in the way of advancement for the local leftist movement. While leftist groups overseas were calling for justice, socialists in Japan – as well as the rest of the nation – found themselves further oppressed under the weight of a new police force as well as the ever-strict state. The social order was not going to be taken down by a minority faction under any circumstance.

For as long as there had been a strong centralized government in Japan keen on keeping the country in a state of conformity, there have been minor factions who leaned away from that doctrine towards what is considered the left of the political scale. As Japan emerged from its isolation throughout the 19th century, the Japanese people became more and more connected to the vast array of societal and political norms that existed beyond their borders; one of them of course being the growingly popular leftist end, what would come to be known as Socialism. As early as 1900 the Japanese government passed new laws that made it illegal for worker groups and unions to demonstrate or even form, stating that they were “a disturbance to the public peace” and effectively stripping them of all practical power1(18). Of course, that did little in the way of deterring those who felt strongly about their cause, people like Kōtoku Shūsui, who came to stand “at the forefront of successive waves of radical political philosophies and movements” 2(198). He had been involved with various radical events leading up to the incident of 1910 and was the kind of charismatic man who was capable of drawing like-minded people to him, even in an extremely nationalistic country like Imperial Japan. Because of this – and the fact that the details of the trial were withheld for so long – not much is known about many of the others involved in the incident.

Emperor Meiji c.1890

Emperor Meiji c.18903.

In May of 1910 police raided the home of Kōtoku and, upon finding materials used in the manufacture of explosives, immediately arrested him and his associate, Miyashita Takichi for the crime of plotted assassination, despite the fact that they and a few others only discussed the idea 4(1). Over the next couple of months following the initial arrests police dug into the lives of these men and rounded up as many people as they could link to the socialist/anarchist movement (the two were deeply intertwined in early 20th century Japan). Eventually they were able to round up and arrest twenty-six people, one of them Kōtoku’s lover, for the same crime and for the remainder of the 1910 trials were held in secret by the highest level of the Japanese court system, the Court of Cassation. Finally, on January 18, 1911 twenty-four of the twenty-six accused were handed death sentences, while the other two got life in prison with hard labour. During the trial process, the defendants were denied council with their lawyers as well as any other kind of external contact, which made it easy for the government to keep it out of the press. It was also determined that not all of those arrested were equally guilty in their association with the leftist movement or else had alibis distancing them from the plot. Within the next week, twelve people got their sentences reduced to life with hard labour and those very fortunate two had their sentences lowered as well. Just six days after the initial court ruling, ten men - including both Kōtoku and Miyashita – as well as Kōtoku’s lover and the sole woman, Kanno Suga, were hanged for treason.

Kanno Suga

Kanno Suga, the only woman to be hanged for treason in Japan5.

International Reactions and Contexts

In Umemori Naoyuki’s article on the historical context of the high treason incident he makes a comparison to an event that happened in 1909 during which a Korean independent activist, An Jung-geun, assassinated four-time Prime Minister of Japan and Resident-General of Korea, Itō Hirobumi. Unlike the trial that followed in 1910-1911, An’s trial was held in a public forum in the district court and, more interestingly, he was tried on his ideology rather than his actions. During the interrogation, the prosecutors attempted to convince An of the errors of his ways by legitimizing Japan’s policy of making Korea a protectorate. The protocol also informs us that his effort at persuasion was made, at least partially, by referring to concrete historical examples and contemporary international conditions. For example, the prosecutors attempted to convince An that his attitude toward Japan was mistaken by educating him about Itō Hirobumo’s life story6(56).On the one hand a Korean nationalist who has succeeded in assassinating a Japanese statesman, was tried in a public forum for all the world to see, pitied by many under the misconception that An had been ruled by blind ideology and for not knowing any better, and ultimately hanged for his crime. The punishment was arguably appropriate for the crime of murder. On the other hand a group of Japanese socialists, only six of whom admitted to plots of assassination, were tried in secret by the highest level of the courts, and sentenced to either death or hard labour despite not actually having done anything but talk and protest661). Considering the mindset of the time in Japan, these reactions are not surprising. It is known that the Japanese had a kind of hierarchy in place within their society that dictated a person’s importance based on their socio and economic standings. In this view people from outside the country’s borders were seen as lesser beings, even the people of Korea who were for intents and purposes part of the Japanese Empire by 1909. By that logic, Kōtoku and his people were treated more harshly because they were part of this cultural identity and supposedly knew better, whereas An was outside this ideal and so could not be blamed for knowingly destroying this social order.

When word did finally break about what had happened to the high treason defendants, socialist groups around the world exploded in protest. While there had long been a minority faction of socialists of various forms in Japan, once news of the charges and the subsequent punishments began to spread, the wider population was shocked and came to fear socialism. This public fear backed the Japanese state’s antagonistic view on socialism, which was arguably the whole point of so harshly trying those accused for their political stance, and resulted in a ramping up of the police system and the creation of a specialized police force to combat the issue1(18-19).

Meanwhile overseas socialists, a surprising number of them being Jewish, rallied around the events of Japan’s high treason incident and used it as a lightning rod to draw attention to how current political systems were not working. An anonymous letter published in the London-based Yiddish newspaper, Arbeter Fraint, said that with the execution of these socialists Japan “had joined the club of ‘civilized nations’ in the world. By the term ‘civilized’, the author seems to be highlighting a negative quality of European “civilization’, namely that it suppresses the freedom of its people”7(86). However, these were the voices of people who did not successfully reach the ears of the general public, wherever they were in the world.

Consequences on the Home Front

For some people living in Japan the high treason incident and subsequent reaction of the state did little to affect the lives of those who embraced socialism not so much as an act of opposition to nationalism, but simply as a way of life. Some men, like Dr. Saburō Ōkita, were able to thrive within the confines of imperialist Japan while still maintaining support for and belief in leftist ideologies. In 1939 Saburō joined the Showa Institute, an organization of educated men with leftist ideals who gathered to lecture graduate students about seriously considering the future of Japan8(14-15). Saburō comments that some of the young men he attended the Institute with became politicians, businessmen, bureaucrats, and even members of the official Communist Party. Saburō himself was a specialized engineer who worked in the Research Division within the Ministry of Greater East Asia 820). Even though the Institute disbanded of their own accord in 1941, they never came directly under the threat of the Japanese state or police. They served as a great example of what socialism could be; educated people who took note of what worked and what didn’t within their country and sought to make things better in the future. The men who were involved with this institute very clearly understood what kind of world they were living in and they knew that their political stances would not be tolerated by the state. They knew that theirs was not a perfect situation politically, but they continued to operate within it as they were expected to and kept their beliefs and ideals amongst themselves. While this does not exactly excite the blood the way demonstrations and protests do, but it stems from the same school of thought and, as history has shown, was the less life-threatening of the two options.

Around the same time young Ōkita was coming to terms with his personal ideologies, the state made plans to shape the future generation. On November 3, 1910 the Army Reservists Association was established with the aim of “producing ‘national villagers,’ subjects imbued with the honest virtues of the land and the army camp”9(170). This fit perfectly in with what then-Prime Minister Katsura Tarō believed the people of Japan needed. He was familiar with the writings of Kōtoku Shūsui and believed that in order to stamp out socialist ideals among Japan’s youth, militaristic discipline was required at all levels of society. However, the high treason incident directly threatened his goals of subduing Japan’s socialist population by drawing the attention of his international connections in America and Russia to what was going on in Tokyo. He even offered to resign as Prime Minister after the incident, considering the negative attention it attracted, but since he was still embroiled in treaty revisions with these Western powers the Emperor refused his offer 9(171). He was just going to have to handle it.


After World War II had ended and Japan had surrendered to the Allies, the Japanese Emperor made a public declaration to his people on New Year’s Day 1946; he declared that he was not a divine being, but simply a man of flesh and blood. Quite simply, and without much fuss, the Emperor confirmed what Kōtoku Shusui and his comrades had plotted to prove with drama and violence back in the spring of 1910. The goal behind what prompted the high treason incident was achieved – even if only five of the twenty-six were alive to see it – despite that the country still remained a nationalist-centered one ruled by discipline and order. Japan had succeeded in joining the ranks of Western countries, complete with their fair share of colonialism, international cooperation, and attempted political assassinations.

Featured Image:

Four Japanese radicals: Kōtoku Shūsui, Sakai Toshihika, Ishikawa Sanshirō, and Nishikawa Kōjirō10