A “nio-mon” is a type of gate with statues of Nio Guardians (Kongorikishi statues) on each side to ward off evil. The solid gate has a double-layered roof, which was built not for practical purposes but to indicate the formality of the structure. That is why there are no rooms on the second floor. The upper parts of the pillars have decorations that at the time of construction were state-of-the-art, testifying to the innovative design of the gate built deep in the mountains. A sign staked to its ridgepole indicates that construction began in 1242, and was completed in 1253. Then in 1954, it became the only structure in northern Kyoto to be designated as a national treasure.

The two Kongorikishi statues of the Nio-mon Gate form a pair known as “Nio-san.” Nara-enkengo-o, the Agyo statue with its mouth open, portrays open anger, while Misshaku-kongorikishi, the Ungyo statue with its mouth closed, portrays inner anger. Together they prevent evil from passing though the gate. They were carved by Higo Jokei, who inherited the Keiha school of Buddha statues, and were installed when the gate was built. Horyuji Temple, Todaiji Temple, Kinpusenji Temple and this Komyoji Temple are the only places where national treasures or important cultural properties are found inside a gate designated as a national treasure itself. They were designated as Important Cultural Properties in 2019.