What to read after Karate-dō?

Linking the time when karate was a strictly Okinawan art of self-defense shrouded in the deepest secrecy and the present day, when it has become a martial art practiced throughout the world, is Gichin Funakoshi, the "Father of Karate-do." Out of modesty, he was reluctant to write this autobiography and did not do so until he was nearly ninety years of age. Trained in the Confucian classics, he was a schoolteacher early in life, but after decades of study under the foremost masters, he gave up his livelihood to devote the rest of his life to the propagation of the Way of Karate. Under his guidance, techniques and nomenclature were refined and modernized, the spiritual essence was brought to the fore, and karate evolved into a true martial art.