Reiki is a generic word in Japan, and is used to describe any type of healing work based on life force energy. It is not exclusive to the system of healing based on Dr. Usui's method. The system of healing that evolved from Dr. Usui's method is called the Usui System of Natural Healing or Usui Shiki Ryoho. It is a type of Reiki.

Since neither Dr. Usui nor Dr. Hayashi left written instruction about Reiki, the only source of information on the Usui System of Reiki comes from the verbal instruction Mrs. Takata passed on to her students.

The Usui System of Natural Healing has evolved over time. In its current state, it is much more organized and structured than the simple, flexible, intuitive method practiced by Dr. Usui. The following is a description of the evolution of the Usui System of Reiki.

The ancient healing method of Reiki was re-discovered in the middle of the 18th by Dr. Mikao Usui, who was also responsible for its revival. Dr. Mikao Usui was the Principal of a christian seminar in Kyoto, Japan. One day, some students asked him about the healing methods used by Jesus christ and whether he would be able to carry out such a healing for them. Usui was stunned and unable to answer these questions. On that day Usui resigned his position and determined to find the answers of this mystery.

His journey led him to America, where he attended the university of Chicago and became a doctor of theology. However, he could not find a satisfactory answer in christian writing and not having found one in chinese scripts either, he travelled to North India, where he studied the holy writings. He later returned to Japan, where he discovered some sanskrit formulas and symbols in old Buddhist sutras which seemed to hold the answer to his questions.

Realizing that he had found the key to the healing, then he began to mediate and cause to the conclusion that he should proceed to a sacred mountain about 17 miles from kyoto, mount Koriyama and commence a 21 day fast and meditation in the hope of gaining contact with the level of consciusness the sanskrit symbols had been written on in order to determine the truth of their contents. He came to a specific spot facing east, and gathered up a pile of 21 stones which would be his calender. On the 21st day he saw a flicker of light appear. It began to more very rapidly toward him. It became bigger and bigger and finally hit him in the middle of the forehead. Usui thought he was dead. However, he was alive but had merely lost his consciousness. He was in an euphoric state. He was millions and millions of rainbow bubbles, soon they became white glowing bubbles each one containing a three-dimensional sanskrit character in gold and he said, ''Yes, I remember.''

Dr. Mikao Usui left mount Koriyama knowing how to heal as Buddha and Jesus had healed, walking down the mountain he experienced what is traditionally known as four miracles.

First, he stubbed his toe walking. His palms turned hot and the torn toe was healed.

Next, he reached a home that several travellers at the foot of the mountains, and ordered cold rice and cold tea, a full meal, not wise after twenty-one days fasting on water, but eat it without discomfort.

Third, the girl serving the meal was afficted with toothache and placing his palms on her Jaw, he healed her pain.

Last, when he reached the monastery at Kyoto, the abbot was in bed with arthritis, Usui healed the monk. Thus was the birth of usui system of Reiki.