The Book of the Samurai was dictated by Yamamoto to his scribe. It was written to bring back and strengthen the samurai ethic and spirit. He felt that the samurai were becoming too tame during peacetime and protested in the Book of the Samurai. It also reflects the changed circumstances of the warrior class after the end of Japan’s century of civil war.
The samurai must be selfless and loyal to his retainer. They must be able to judge when their retainer is ready to receive information and must completely trust him. The samurai must be close to his retainer, praising and encouraging him.
One must suppress a yawn because it is bad taste to yawn in front of people. The book includes instructions on seemingly inconsequential