In the mid-6th century a delegation sent by a Korean prince arrived at the court of the Emperor of Japan. The Koreans brought with them Buddhist sutras, an image of Amitabha Buddha, and a letter from the Korean prince praising the dharma. This was the official introduction of Buddhism to Japan.
Today an ancient Buddha image said to be the one from the Korean delegation is enshrined at Zenkoji, a temple in Nagano. The image, the Ikko-Sanzon Amida Nyorai, is also called the hibutsu, the "secret Buddha," and the public is never allowed to see it. Instead, a replica is displayed every six years.
Beside the hibutsu, another well-known feature of the temple is a pitch-black, narrow corridor beneath the main hall. People go through the corridor, feeling the wall for an old metal handle. According to legend, if you touch the handle you will be guaranteed liberation from samsara.
Zenkoji was established in the 6th century, but most of the structures in the temple complex today date from the 17th and 18th centuries. It is shared and jointly managed by the Tendai and Jodo Shu sects.