A man wielding a dagger was subdued as he was about to attack Sanzō Nosaka, the chairman of the Japanese Communist Party.

Sanzō Nosaka was a Japanese writer, editor, labor organizer, communist agent, politician, and university professor and a founder of the Japanese Communist Party (JCP). He was the son of a wealthy Japanese merchant, and attended Keio University. While in university, Nosaka became interested in social movements, and joined a moderate labor organization after graduation, working as a research staff member, and as a writer and editor of the organization's magazine. He traveled to Britain in 1919 to study political economy, where he deepened his studies of Marxism and became a confirmed communist. Nosaka was a founding member of the Communist Party of Great Britain, but his activity within British communist circles led to him being deported from Britain in 1921.