Bansenshukai

Bansenshukai (萬川集海, translated 'Sea of Myriad Rivers Merging') is a collection of ninja knowledge widely regarded as being written by Fujibayashi Sabuji, Fujibayashi Yasutake, or Fujibayashi Yasuyoshi. Written in 1676, it is a culmination of philosophy, military strategy, astrology, and weapons beliefs of the times.