Rengein-Tanjyoji temple, the Kyushu-district head temple of the Shingon-ritsu sect of Buddhism (esoteric Buddhism), is dedicated to the Buddhist Saint Koen.

St. Koen was born to a noble family on the very site of Rengein-Tanjyoji temple in 1073, in the Heian Era, the eras of the aristocracy. Holding the reins of Higo province government, his grandfather, Lord Shigefusa Fujiwara,(Kanpaku; the highest rank of courtiers). St. Koen entered the priesthood in his infancy. He studied Buddhism and practiced Buddhist training asceticism at Mt. Hiei near Kyoto. When he was young, he was very famous as a great priest, as well as being a profound Buddhist scholar in Japan. He wrote "Fusoryakki," which is numbered among the three great chronicles in Japan, including"Dainihonshi" and "Nihonshoki". He also educated thousands of disciples. At the age of 74, he granted the fundamentals of Jyodo Buddhism to 15-year-old Honen who then founded the Jyodo Sect (the Pure Land Sect) and became the master of the priest Shinran.

Because of St. Koen's vow to attain a miraculous power to save mankind, he entered Nirvana as a dragon-deity incarnate at Sakuragaike-pond in Shizuoka prefecture in 1169. Subsequently he received Bosatsugyo-training asceticism in the next world.

        dragon-deity: believed to have great divine vitrue 
                      to save people.
        Bosatsugyo  : said to be the most holy training in
                      Buddhism for becoming the savior of 
                      the world.

In 1177, Lord Shigemori Taira built "Rengein temple" or the original of Rengein-Tanjyoji temple. In 1225 under the authorization of the emperor, the priest Eku founded solemn "Rengein-Jyokoji temple" and the huge stone pagodas or "Kanpakuto" in the birthplace of St. Koen to pray for the repose of the souls of St. Koen and Kanpaku Michikane Fujiwara. Unfortunately the temple was burnt to the ground during the war in 1582.

In 1930 the archbishop before last Zeshin, inspired by the revelation of the Dragon-deity St. Koen, rebuilt the temple and named it Rengein-Tanjyoji temple. Zeshin then became the successor to St. Koen. Following St. Koen's teachings and inspired by the divine power that he had achieved during his 760-year-long Bosatsugyo practice, Rev. Zeshin devoted his life to aiding people suffering from disease and disaster.

Today, the divine virtue of St. Koen shines a light of mercy and offers salvation to all people throughout the country. In 1978, on the 800th anniversary of the nirvana of St. Koen, Okunoin was established as a subsidiary temple of Rengein Tanjyoji at the wish of Rev. Zeshin. And now, new wooden five storied pagoda is under construction at the main temple and the opening ceremony will be held on April 12 and 13 in 1997.