Koka One-Hundred-Member Gun Squad, referred to as Koka Hyakunin-gumi, were Tokugawa Shogunate’s forces who lived in Edo (present-day Tokyo) to guard the Ote San-no-mon Gate of Edo-jo Castle. The ancestors of Koka Hyakunin-gumi were Koka clans who fought on the side of Tokugawa forces at Fushimi-jo Castle and lost many of its warriors during the preceding battles of the Sekigahara Battle in 1600.
In 1849, Kurokawa Masutaro and Goto Kitsujiro from the Koka Hyakunin-gumi visited Jigen-ji Temple. They built a tombstone for the memorial service of their ancestors and placed ancestral tablets with the names of Koka warriors who died in the battle at Fushimi-jo Castle in the temple.
The Koka Hyakunin-gumi cherished their roots even through the generations and changes in their location of residence. The tombstones and tablets are carefully protected to this day, and the accomplishments of the Koka clans, also known as the Koka ninja, continue to be passed down through the generations.