Mikao Usui was the founder of a form of spiritual practice known as Reiki, used as a complementary therapy for the treatment of physical, emotional, and mental diseases. According to the inscription on his memorial stone, Usui taught Reiki to over 2000 people during his lifetime. Sixteen of these students continued their training to reach the Shinpiden level, a level equivalent to the Western third degree, or Master level. Usui died on 9 March 1926 of a stroke.