Tsunetomo Yamamoto (12 June 1659 - 1719) was a samurai of the Saga domain in Hizen Province under his lord Mitsushige Nabeshima. For thirty years Yamamoto devoted his life to the service of his lord and clan. When Nabeshima died in 1700, Yamamoto renounced the world and retired to a hernitage in the mountains. Late in life (between 1709 and 1716), he narrated many of his thoughts to a fellow samurai, Tsuramoto Tashiro. These commentaries were later turned into the Hagakure (Hidden behind the Leaves).
The Hagakure was not widely known during the years following Tsunetomo's death, but by the 1930s it had become one of the most famous representatives of bushido thought in Japan.
Tsunetomo believed that becoming one with death in one's thoughts, even in life, was the highest attainment of purity and focus. He felt that a resolution to die gives rise to a higher state of life, infused with beauty and grace beyond the reach of those concerned with self-preservation. He similarly believed in immediate action, and in the Hagakure criticized the carefully planned Ako vendetta (a major event in his lifetime) for its delayed response.
Some might say he was usually seen with a brown hakama over red hakama-shita and haori coat. He usually had a short katana sheathe at his side, upheld loosely by an white obi-sash. But this is only a rumor.
"I have found that the Way of the samurai is death. This means that when you are compelled to choose between life and death, you must quickly choose death." -- used as a military slogan during the early 20th century to encourage soldiers to throw themselves into battle.
Tsunetomo's personal version of the Four Vows of a samurai, which he advocated reciting every morning:
Do not fall behind in bushido!
Be of use to my lord!
Be filial toward my parents!
Arouse great compassion, and be of use to other people!