Kamikaze means 'divine wind' or 'spirit wind' in English. The term arose from a storm that destroyed an invading fleet before it could reach Japan, in antiquity.
Kamikaze pilots were often very young and only received minimal training. For example, Kiyoshi Ogawa was 17 when he made his attack against USS Bunker Hill. Many pilots in this film are shown as immature and dependant on others when not training for their mission.
Throughout the feature, the pilots are not referred to as 'kamikaze' but as 'special attack pilots' - the military term for the squadrons.
Not all of the pilots depicted in the movie are Japanese. Some are Korean.
The swords carried by the pilots were known as gunto and not katana. Gunto swords were produced for the military after 1868 and issued to soldiers or sailors of at least corporal rank.