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, Ishikawa Yozaemon, Matsumura Hyoemon, and Hayashiguchi Yoemon from the Hyakunin-gumi visited Shomyo-ji Temple to hold a memorial service for their ancestors. The tomb of Yamaoka Kagemitsu who led the Koka clan warriors in the Battle of Fushimi-jo Castle remains in the temple.
The remaining tombstones demonstrate the respect Koka Hyakunin-gumi had towards their ancestors and how they cherished their roots.