When Nichiren Shonin visited Mount Minobu on May 17, 1274, he was welcomed by Nambu Sanenaga at what is called the “Oshima Remains,” where a rock that Nichiren Shonin sat to rest remains. In addition, in order to pass this memorial site down to future generations, the main gate was built in 1665. When welcoming Nichiren Shonin, Nambu Sanenaga stated that he would worship and serve him as long as he lived, and asked the next generation to serve him after he died. He also donated Mount Minobu to him. On June 17, 1274 which was about one month after he arrived at the mountain, a thatched hut where Nichiren Shonin would live was completed. This was determined on the day Kuon-ji Temple was founded, and Minobusan (Mount Minobu) Kaibyaku-e (a celebration for the foundation of Minobusan (Mount Minobu) Kuon-ji Temple) is held each year.