Priest Ryuko隆光's tombstone is found in the following four places. (1) Toshodai-ji 唐招提寺, (2) Muro-ji 室生寺, (3) Otokuni-dera 乙訓寺, (4) the ruined Chosho-ji 超昇寺止. We can add (5) the ruined Tsubo-ji 通法寺肚 to this list.
It is said that the Tsubo-ji which existed at Tsuboi 壺井 in Kawachi 河内国 began with an inn constructed in 1020 by Minamotono Yorinobu 源頼信, fourth son of Tada Mitsunaka 多田満仲 and with the birth of his son Yoriyoshi 頼義, his first son Yoshiie 義家, his second son Yoshitsuna 義綱 and his third son Yoshimitsu 義光 it became the base of the main line of the Kawachi Genji 河内源氏, with its main image a thousand-armed Kannon 千手観音, which Yorinobu 頼信 obtained on his way to a hunt. This is the origin of this temple in 1043 with the establishment of a Kannon-do 観音堂 on the south side in his residence. After his retirement Yoriyoshi 頼義 became a monk and established the Tsubo-ji. This place preserves the 3 tombstones of Yorinobu 頼信, Yoriyoshi 頼義 and Yoshiie 義家. But, there is a description of Yoshiie's 義家 fifth son Yoshitoki 義時 worshipping the souls of the aforementioned three generations, and establishing the Tsuboi-jinja 壼井神社 in 1109, and establishing the Tsubo-ji in 1048 as the family memorial temple. If the latter date were closer to the former, it would be more pursuaslve.
After that, three times it was burned in war. In more recent times it became the memorial temple of the Tokugawa 徳川 clan founders, being rebuilt in the Genroku 元禄 period (late 17th c.), the efforts of the Priest Ryuko 隆光 being especially important.
However, with the shogunate's collapse, this temple too became weak, In 1871 the temple lands were confiscated, and in 1873 the temple was abandoned to ruin, the buildings completely destroyed. The present-day gate and bell-tower are post-World War II restorations.
At present there exists a Tsuboi-dera 壼井寺, but this has no relation at all with Tsubo-ji.
On September 3, 1514 in the Tsubo-ji, Shogu 称愚 received the name Yugya 遊行 from the twenty-second Yugyo, Igyo 意楽, becoming the twenty-third Yugyo. In other words, at this time this was a temple of the Yugyo Jishu sect 時衆.
According to legend, Shinran's 親鸞 mother was the daughter of Minamotono Yoshiie's 源義家 legitimate son Yoshichika 義親. There is a strange story which was created in recent times that it is possible she was born in the extension at Tsubo-ji. It is said that Yoshichika committed murder and mayhem hither and yon until subdued in January 1108 by Taira no Masamori 平正盛, grandfather of Taira no Kiyomori 平清盛. If we suppose this daughter was born in 1108, since Shinran was born in 1173, her mother would have given birth at age 65.