Wait, won't the momentum of the plane carry it into the carrier regardless of if the pilot gets killed by a bullet before he hits it?
The Japanese didn't call themselves Kamikaze at all. That was a US term given to them. Kamikaze translates to something like Divine Wind. They use the word tokkotai or even shinpu. Japanese kamakazi pilots were not forced to do what they did. Many were students trying to prove themselves as warriors (the feudal japanese bushido code) and the Japanese in fact had more volunteers than actual planes. Anyway, during the second world war, pilot helmets wouldn't offer them any realistic ballistic protection at all. Most were made out of tough leather and a musket shot could probably penetrate it. However, the real reason the kamikaze pilots wore helmets is because it was critical to fly the plane for it housed communications equipment and many of the issue goggles were attached.
That SpuriousMonley is smart. The Planes had to be landed in a way to make maximum damage to the American ports, hence had to land at full speeds at almost 90degrees, hence the Helmets.