He began reading the works of Marx and Lenin as well as leftist magazines. In April 1921, he was affected greatly by Professor Kawakami Hajime's article on Russian Revolution. He was convinced that the revolution succeeded because dedicated terrorists made sacrifices. The following month's newspaper account about the High Treason Incident increased his indignation at the government. In late 1923, angered by the murders of Japanese anarchists and Koreans during the panic of the Great Kanto earthquake, he made up his mind to carry out the assassination.