Isshinji Temple is said to have been founded by Honen in 1185.

In 1600, the year of the Battle of Sekigahara, the son of Tokugawa Ieyasu died young, and his funeral was held at Isshinji Temple. Since then, it has had strong ties with Lord Ieyasu, and during the Winter Siege of Osaka in 1614, Lord Ieyasu's headquarters were located here.

The most distinctive feature of Isshinji Temple is the construction of a bone Buddha. Every 10 years since 1887, we have been constructing and holding a memorial service called ``Otsubutsu'', which is a Buddha statue made by condensing interred remains into powder. Currently, about 2 million deceased people are enshrined in the form of Amitabha Buddha in Isshinji Temple's Ossuary Hall.