She died in clashes between demonstrators and police at the South Gate of the National Diet Building in central Tokyo at the climax of the 1960 Anpo Protests against the US-Japan Security Treaty.

Kanba's death was widely covered at the time, and is seen as a symbol of the 1960 mass protests against the revised Treaty of Mutual Cooperation and Security Between the United States and Japan.

A political cartoon that ran in the popular journal Sekai a month after Kanba's death depicted a yakuza gangster lighting a cigarette for a policeman as they both stand over her dead body in front of the National Diet Building.

[6] Historian Nick Kapur argues that nationwide shock at Kanba's death helped force the resignation of Prime Minister Nobusuke Kishi and the cancellation of a planned visit to Japan by U.S. President Dwight D.

[7] Kapur says Kanba's death was viewed as a "triple tragedy," first because she was so young, second because she was a student at Japan's most elite university, and third, because she was a woman, at a time when it was still novel for women to participate on the front lines of street protests.