The So-mon main gate faces national road No.52. It is the entrance to the sacred area of Mount Minobu. A tower with an inscription of nam-myoho-renge-kyo stands near the gate as the enclosure to separate the spiritual realm of Buddhahood and the ordinary world. The main gate stands at the site where Nichiren Shonin entered Mount Minobu and was welcomed by Nambu Sanenaga. Passing through the gate, visitors see the Oshima Remains where Nichiren Shonin sat to rest. This gate was donated by the mother (Juoinden Myoso Nikkaku Daishi) of Miura Yasuji, the Governor of the Shima Region and the lord of Kariya Castle, in 1665. This is why the gateposts have the crest of the Miura Clan (three bars in a circle). The three characters, kai-e-kan, on the board hanging under the roof of the gate were written by Niccho Shonin, the 36th head priest of Kuon-ji Temple. Kai-e means that everyone becomes a Buddha with the Lotus Sutra.