Bansenshūkai

Bansenshūkai (萬川集海, Ten Thousand Rivers Flowing Together to form an Ocean) (Also pronounced Mansenshukai) is a 1676 Japanese book containing a collection of knowledge from the clans in the Iga and Kōga regions that had been devoted to the training of ninja. Bansenshūkai summarizes the main points of the three volumes of the original Ninjutsu book Kanrinseiyō (間林清陽), and was written by selecting only those that fit the times. In the beginning of Bansenshūkai, the existence of the original text Kanrinseiyō was mentioned, but its existence had not been confirmed for a long time. However, in June 2022, a manuscript of the second volume of Kanrinseiyō copied in 1748 was found.