This practice, known as sokushinbutsu, was pioneered by a Japanese priest named Kūkai. Dainichibō Temple, Ōami, Tsuruoka City, Yamagata Prefecture. Dainichibō Temple, Ōami, Tsuruoka City, Yamagata Prefecture. At the end of this period, the tomb was opened to see if the monk had successfully embalmed himself. It is believed that several hundred monks attempted sokushinbutsu, but only 28 of them are known to have successfully embalmed themselves.