[1] On 20 May 1910, the police searched the room of Miyashita Takichi (1875–1911), a young lumbermill employee in Nagano Prefecture, and found materials which could be used to construct bombs.
Investigating further, the police arrested his accomplices, Nitta Tōru (1880–1911), Niimura Tadao (1887–1911), Furukawa Rikisaku (1884–1911) and Kōtoku Shūsui and his former common-law wife, feminist author Kanno Suga.
These included Shūsui,[1] a prominent Japanese anarchist, Ōishi Seinosuke, a doctor, and Uchiyama Gudō, the only one of the Buddhist priests arrested to be executed.
During the High Treason investigation, anarchists already incarcerated were questioned about possible involvement, including Ōsugi Sakae, Sakai Toshihiko, and Yamakawa Hitoshi.
The High Treason Incident created a shift in the intellectual environment of the late Meiji period towards more control and heightened repression for ideologies deemed potentially subversive.