There has been a lot of speculation about where Reiki came from, but there has been little confirmation of most of these ideas. Some say that Reiki originated from Buddhism or that it contains Buddhist concepts or techniques. I spoke with a Japanese Reiki master who is also a Buddhist and has done historical research into Reiki in Japan. He said that he could see no connection between Reiki and Buddhism and that he felt that Reiki is religiously neutral. While Dr. Usui may have been a Buddhist, he had also studied Christianity and had lived with a Christian family for a time. It is clear he had a very broad background in many religious teachings and philosophies
The clearest and most authentic understanding we have been able to discover is that Dr. Usui originated the system of healing he taught and practiced based first on his mystical experience on Mt. Kurama and then later by making use of his studies in many different areas of knowledge. Usui Reiki has no connection to Buddhism, nor is it connected to Tibetan Buddhism or Tibetan shamanism or any other religion. One of the stories says Dr. Usui discovered the Reiki symbols in a Tibetan sutra, but even though people have carefully looked, no one has been able to find a Tibetan sutra with Reiki symbols in it. This is further validated by Dr. Usui’s own writing in which he says, "Our Reiki Ryoho is something absolutely original and cannot be compared with any other (spiritual) path in the world."