From a standpoint of our modern, western culture, it makes no sense. From the standpoint of traditional Japanese cultural values they believed in, in which included the divinity of the Emperor and less value placed on individual survival than on fulfilment of the Emperor's orders, it makes perfect sense. The Emperor, practically a god on Earth, through his military commanders, ordered these men, who considered themselves to be the modern samurai and hence above such base urges as personal survival, to attack his enemies by piloting aircraft into their ships. It seemed reasonable to a people who considered it shameful to surrender, and who chastised those who survived a defeat by telling them that they didn't deserve to die for the Emperor.
So in short, it is a higher cause, to preserve the Emperor, and in their way, honour.
I hope this answer isn't too late, and I truly apologise if this answer has strayed from the right answer.
