Honmyō-ji is a Buddhist temple of the Nichiren sect, Rokujōmon-ryū, in Nishi-ku, Kumamoto, Japan. It is the most high-ranking temple of the sect in Kyushu. In Honmyō-ji is the grave of Katō Kiyomasa, a Japanese daimyō, builder of Kumamoto Castle and a dedicated buddhist of Nichiren Buddhism.