At each one the priests said they were more concerned with spiritual than physical well being. In one small monastery he found some ancient Sanskrit writings from India (or perhaps Tibet). [Diane Stein's research suggests he found the sutras to invoke the Medicine Buddha, the invoking of this Buddha is a common practice in Tibetan Buddhism] After a few more Years of study, he felt he had come to an understanding and that to go further required in depth meditation. He declared to the monks his intention to fast and meditate for 21 days at a nearby mountain and that if he did not come back they should come and get his body. As the story has it, Usui went to a meditation spot at Mount Kurama-yama and undertook an intensive practice utilizing some the practices he had studied. During his "satori" experience, he came to the realization of how working with divine "Ki" energy might assist him in some of his difficulties. Eventually, through the years of study and practice Usui was able to meld together a method for bringing the essence of these Buddhist practices together in a way he could work with. Later on, it became known as Reiki.
He first practiced his newly discovered method on himself and friends. This gave him an opportunity to perfect and refine his new healing method. Meanwhile, he continued to hold regular meetings for his growing circle of Buddhist followers, and further developed and refined his system.
In 1922, Usui moved to Tokyo where he opened a Reiki clinic in Harajuku, outside of Tokyo. He began to set up classes and teach his system of healing - Reiki. He also began to utilize a small manual, which contained the Precepts, Meditations, and Japanese poetry (Waka) - but no hand positions of any kind were mentioned.
His teachings seemed well received by the older generation, as they viewed them as a return to older spiritual practices that they were familiar with. Usui trained a very small number to the Shinpiden (Master) level. They were 5 Buddhist nuns, 3 Naval officers, and 9 other individuals.
On September 1, 1923, the devastating Kanto earthquake struck Tokyo, and the surrounding areas. Most of the central part of Tokyo was leveled and totally destroyed by fire. Over 140,000 people were killed. The wood houses quickly ignited as they collapsed from the tremors. Three million homes were destroyed leaving countless homeless. Many thousands suffered serious injuries. The public water and sewage systems were destroyed. It took years for the rebuilding to take place. In response to this catastrophe, Usui and his students offered Reiki to countless victims. His clinic soon became too small to handle the throng of patients, so in February of 1924, he built a new clinic in Nakano - outside of Tokyo. His fame spread quickly all over Japan, and he began receiving invitations from all over the country to come and teach his healing methods.
He received an award from the Emperor, for having done extremely honorable work. His fame soon spread throughout the region and many prominent healers and physicians began requesting teachings from him
During this time, Usui quickly became very busy as requests for teachings of Reiki continued to grow. He traveled throughout Japan (not an easy task in those days) to teach and give Reiki Empowerments. This started to take its toll on his health and he began to experience difficulties from the stress. Finally, on March 9, 1926, while in Fukuyama, he died of a fatal stroke; he was 62 years old..His body was cremated and his ashes were placed in a Temple in Tokyo. Not long before his death, the Reiki Society (Gakkai) was formed. The remaining students of this organization met in Tokyo to erect a memorial stone to Usui at Saihoji Temple in the Toyatama district of Tokyo.
According to the inscription on his memorial stone Usui taught Reiki to over 2,000 people, even though we believe that this number simply denotes "a large number" of students. Many of these students began their own clinics and developed Reiki schools. By the 1940's there were about several Reiki schools spread all over Japan. Most of these schools taught the simplified method of Reiki that Usui had developed.