Be always pure-hearted and cheerful.
A loyal fighting man is a pure-hearted and filial son.
Attain a high level of spiritual training.
In order that you can exert the highest possible capability, you must prepare well your inner self. Some people say that spirit must come first before skill, but they are wrong. Spirit and skill are one. The two elements must be mastered together. Spirit supports skill and skill supports spirit.* Extract: Kamikaze pilot's manual.