Written in 1768 by Kashibuchi Arinori, "Gekiken Jintsuu Roku" is an ancient book on the martial arts of Japanese fencing, using a more olden style of Kendo armour and even practicing with a padded Spear!
More interestingly, 75% of this book was written in classical Chinese, instead of Japanese.
A valuable reference in understanding the exchanges in Chinese-Japanese martial arts & language, and the history of sparring freeplay in weapons-based martial arts.