The Founder and his Son
Ryuganji is a temple of the Jodo sect of Buddhism, and according to a document left by its former abbot, it was founded in 1616 by the monk Yasui Santetsu. He was an unknown monk, but he left his name in history as a master Go player who served Tokugawa Ieyasu, the founder of the Edo Shogunate. Although his death date is inscribed on the existing memorial tablet in the main as 1648, it is generally believed that he passed away in 1652.
Yasui Santetsu’s eldest son was Shibukawa Harumi, who served as the first head of the Edo shogunate’s astronomical office. He was born in 1639 and showed interest in astronomy from childhood. When he was 21 years old, he traveled around Japan to observe celestial bodies, conducted scientific research, and created Japan’s first domestically produced calendar. This calendar was adopted by the shogunate as the “Jokyo calendar,” and in 1684 he moved to Edo (present-day Tokyo) as an astronomer. He died in 1715.
Ryuganji Temple is built on the site of the residence of these two great persons.
Temple Buildings
The present main hall was rebuilt in the mid-Edo period (1684-1688). The Guest hall was built a little later, during the Kyoho period (1716-1736).
The Amitabha Buddha is enshrined in the center of the main hall.
