Establishment and Development of the Koka Shinobi Officials of Owari clan

Abstract

In November 2017, “Somanaka Kimura Honke Documents（杣中木村本家文書）” was found. By comparing the other historical documents, this paper will clarify the process of formation, service, family finances, economy, and espionage activities of “Koka-five-ninja（甲賀五人）” served the Owari clan. There were seventeen Koka ninja in the Owari clan, but they were dismissed, and “Koka-five-ninja” were established after the employment of Kimura Okunosuke, in 1672. Okunosuke visited Koka and made a contract with “Koka-five-ninja,” they inherit ninjutsu called “Kagun （家軍）.” When “Koka-five-ninja” came to Nagoya for target practice, Okunosuke went to visit them at their inn, and when there was an inheritance, he and his son went to Koka to participate the ceremony. Okunosuke had to pay for high cost of living in Nagoya and “Koka-five-ninja” staying at his home, and he became impoverished. The first Okunosuke might be cautious about intelligence activities. The intelligence activities of “Kokafive- ninja” were active only for 16 years, from 1723 to 1739, after Okunosuke’s death.