"The third specialization [of staff fighting] was the art of the wooden sword (bokken), a staff carved and shaped in accordance with the contours of a real sword, often so skillfully that the result became a much appreciated object of aesthetic enjoyment and display. This art is not mentioned as frequently as one might expect, simply because it was linked so closely to kenjutsu that it was generally identified with or subordinated to the latter. Yet most duels among masters of different schools, all the tournaments among clansmen, all the examinations for rank, and so forth involved the use of the sturdy bokken which every bushi used as a part of his training equipment. In certain exceptional cases, it could even be substituted for the katana; for example, when skilled swordsmen became itinerant monks or men of peace and developed an aversion to the shedding of human blood, under any circumstances. In such cases, the bokken was used primarily as an instrument of pure defense."
* Calizzano 1989 p137
"La caste militaire produisit en revanche une version en bois (chêne ou merisier) de l'épée caractéristique des samouraïs (Katana). La Boken, conçue au départ pour l'entraînement, révéla rapidement ses propriétés offensives si bien que de nombreux guerriers l'adoptèrent en remplacement de l'épée en acier. La plus fine lame du Japon féodal, Miyamoto Musashi, utilisa plusieurs fois la Boken pour ses duels l'opposant à des adversaires armés d'un Katana."