Many "kamikaze" pilots offered themselves as volunteers for the mission. They were usually very young, between 18 and 24 years old. Their belief was that dying when striking the enemies of Japan and the Emperor down was a very honorable death. This principle was traditional since the days of the samurai, and gave great importance to the sense of duty and obedience. This idea was called "Giri" (""Obligation""), and was part of the code of conduct of the Japanese warriors since the Middle Ages, the "Bushido". Many young men sacrificed themselves by their free will because these beliefs and their love for the home land were the most important things for them. The "tokkōtai" pilot's manual told pilots to never close their eyes. This was because if a pilot closed his eyes he would miss his target. In the final moments before the crash, the pilot was to shout ""Hissatsu!"" (""Critical Strike!"") as loud as he could.