Ganjoji Temple in Gamo Town in Shiga Prefecture is a historic temple pertaining to Prince Shotoku. It was one of Ganjojuji temples, which were established in 46 places all over the country to fulfill Prince Shotoku’s wishes to bring stability to the nation. It was originally a Tendai-sect temple, but was converted to the Soto sect in 1625 when the temple was restored by the Zen priest Sanei Honshu.

It is the 26th temple of Gamo Kannon Holy Sites, the 9th of Shaka 32 Zensatsu (Zen Temples) and the 24th of the 27 Meisatsu (Fine Temples) in Omi-Koto.

The principal image is a secret Buddha, which is open to the public once every 33 years. It is said that the face was modeled after Prince Shotoku’s mother.

In the Kannon-do Hall, what is believed to be a mermaid mummy is enshrined. According to an old story, the mermaid fell in love with a beautiful nun and visited the temple every day, disguising himself as a young man. A lot of stone art objects made in the Middle Ages are preserved in the main hall.