Japan's banzai attacks were a suicide attack, in a wave charging with their rifles as the bayonets were attached to it, charging while screaming " "Tennōheika Banzai" (天皇陛下万歳)(had to use wiki to paste it here.) on where it translates to "Long live his Majesty the Emperor!" allies call it "Banzai" as the word shouted reads as "Tennōheika Banzai" on where they removed the "Tennōheika" and kept the "banzai" now commander " Tadamichi Kuribayashi" disallowed the usage, as it was a waste of men and manpower, i can agree, but this attack was used in the pacific war more often, as this came from weak Imperial Japanese soldiers during the invasion of china, as they were very effective.. now where did it come from? When i read about "Banzai charge" i saw it was from a very respected Japanese samurai. " The suicide of Saigō Takamori inspired the government that suicide was their final, honorable action. " this is very interesting, as Japan is a modern world, but used to go through wars, and then the emperor used war propaganda that surrendering is not a option. This is all I know, G'bye!
Source: reddit post