
History of the Sainenji

Sect
Jodo sect
financial support
Hattori Hanzo masanari
Buddhist name
Senshoindenanyosainendaizenjomon
Founding
3rd year of the Bunroku era (1594) Senyomujosyonin

Senshozan Annyouin Sainenji was founded as a memorial for Matsudaira Nobuyasu (the eldest son of Lord Tokugawa Ieyasu) with the financial support of "Lord Hattori Hanzo Masanari", a famous ninja. Lord Hanzo Masanari was born in Mikawa Province (Aichi Prefecture) in 11th year of the Tenbun era (1542) as the son of a ninja father, "the first Hanzo Yasunaga".
His father, Yasunaga, was a ninja chieftain, but Masanari himself served as a samurai under Lord Tokugawa Ieyasu. He led the ninjas of Iga and Koka, was a master of the spear, earned the nickname "Oni Hanzo", accomplished many military feats, and received a spear from Lord Ieyasu.
Born as the eldest son of Lord Tokugawa Ieyasu and his wife Tsukiyama-dono, Lord Nobuyasu was known for his great military prowess and had a promising future. He formed an alliance with the Tokugawa family and attracted the attention of Lord Oda Nobunaga, who aspired to rule the country. As a result, Nobunaga's daughter was married to Lord Nobuyasu. However, Lord Nobunaga, driven by fear and suspicion of Lord Nobuyasu's excellence, demanded Lord Nobuyasu's seppuku, citing rumors of his supposed madness. (One theory is that he was suspected of having an inside connection with Lord Takeda Katsuyori.) Unable to disobey Lord Nobunaga's ruthless orders, and in order to maintain the peace of the Tokugawa family and the alliance with the Oda clan, Lord Ieyasu made the agonizing decision to order his beloved eldest son, Lord Nobuyasu, to commit seppuku. When Lord Nobuyasu Nobuyasu committed seppuku, his intercessor was Lord Hanzo Masanari. However, even Lord Masanari, who was nicknamed "Oni Hanzo", could not turn his blade against the lord he served, no matter how much he was ordered to do so, and finally could not fulfill this role. This made him feel the impermanence of the world, and he entered Buddhism to pray for the repose of Lord Nobuyasu's soul.
In 18th year of the Tensho era (1590), Lord Ieyasu entered Edo, where he built Edo Castle and established his headquarters. Lord Hanzo Masanari accompanied him to Edo, where he shaved his head to mourn the soul of Lord Nobuyasu, and took the name "Sainen". He then established a hermitage in Kojimachi Shimizudani (near Shimizudani Park near the present Hotel New Otani), buried the hair of Lord Nobuyasu, which he had kept since Enshu, and spent his days as a full-time Buddhist monk.
It is recorded that in 2nd year of the Bunroku era (1593), Lord Hanzo Masanari received 300 ryo of gold from Ieyasu and was given an unofficial order to build a temple to pray for the soul of Lord Nobuyasu, for the repose of the souls of the loyal Tokugawa family, and to conduct memorial services for those killed in battle. However, he was unable to build the temple, and passed away on November 14, 4th year of the Bunroku era (1595), at the age of 55. The Buddhist name is "Senshoindenanyosainendaizenjomon".
Later, temple was built at the same location, and the Sangō (mountain name), Ingō (kind of temple name), and Jigō (temple name) were taken from this Buddhist name, and the name became "Senshozan Annyouin Sainenji".
