His books on sai , bo , tonfa , and nunchaku are among the most popular in martial arts instructional literature .
Fumio Demura is a Black Belt Hall of Fame member and one of the most respected weapons masters in the world .
Fumio Demura 's books on sai , bo , tonfa , and nunchaku are among the most popular in martial arts instructional literature .
Fumio Demura is a Black Belt Hall of Fame member and one of the most respected weapons masters in the world .