Hagakure ("In the Shadow of Leaves") is a manual for the samurai classes consisting of a series of short anecdotes and reflections that give both insight and instruction-in the philosophy and code of behavior that foster the true spirit of Bushido-the Way of the Warrior. It is not a book of philosophy as most would understand the word: it is a collection of thoughts and sayings recorded over a period of seven years, and as such covers a wide variety of subjects, often in no particular sequence.

The work represents an attitude far removed from our modern pragmatism and materialism, and possesses an intuitive rather than rational appeal in its assertion that Bushido is a Way of Dying, and that only a samurai retainer prepared and willing to die at any moment can be totally true to his lord. While Hagakure was for many years a secret text known only to the warrior vassals of the Hizen fief to which the author belonged, it later came to be recognized as a classic exposition of samurai thought and came to influence many subsequent generations, including Yukio Mishima.
This translation offers 300 selections that constitute the core texts of the 1,300 present in the original.

Yamamoto Tsunetomo (山本 常朝?), also read Yamamoto Jōchō (June 11, 1659 – November 30, 1719) was a samurai of the Saga Domain in Hizen Province under his lord Nabeshima Mitsushige. For thirty years Yamamoto devoted his life to the service of his lord and clan. When Nabeshima died in 1700, Yamamoto did not choose to follow his master in death in junshi because the master had expressed a dislike of the practice in his life. Instead, Yamamoto followed his lord's wishes and refrained from junshi. After some disagreements with Nabeshima's successor, Yamamoto renounced the world and retired to a hermitage in the mountains. Later in life (between 1709 and 1716), he narrated many of his thoughts to a fellow samurai, Tsuramoto Tashiro. Many of these aphorisms concerned his lord's father and grandfather Naoshige and the failing ways of the samurai caste. These commentaries were compiled and published in 1716 under the title of Hagakure, a word that can be translated as either In the shadow the Leaves or hidden 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 taught in Japan. In 2011 a manga/comic book version was published Hagakure, The manga edition.

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. Some viewed him as a man of immediate action due to some of his quotes, and in the Hagakure he criticized the carefully planned Akō vendetta of the Forty-seven Ronin (a major event in his lifetime) for its delayed response.

Yamamoto Tsunetomo is also known as Yamamoto Jōchō, the name he took after retiring and becoming a monk.