When the great Buddhist priest Nichiren was exiled to Sado island for his Rissho Ankoku treatise and other offenses, his disciple, the Buddhist priest Nichiro, a vassal of Hojo Tokiyori, was locked up in the residence of Yadoya Mitsunori.
In time, Mitsunori became a follower of Nichiren, and he converted his residence into Kosoku-ji Temple.
On the hill at the rear of the temple grounds is an earthen jail where it is said that Nichiro was held captive.
There is a monument inscribed with the famous poem Ame ni mo Makezu by Miyazawa Kenji, a devout follower of the Lotus Sutra.
The temple is also known in Kamakura for its 200 year-old chokeberry tree and other varieties of flowers, which can be enjoyed in every season.