Usui Sensei asked Hayashi Sensei to develop Reiki which he did and Mrs. Takata who brought it to the west also changed the way it was practiced. Because of this, the system that has been taught in the west which has in turn spread all over the world is considerably different than the Reiki methods of both Hayashi Sensei and Usui Sensei.
During his mystical experience on Mt. Kurama, Dr. Usui received the ability to do Reiki treatments. Later he added the Reiki Ideals, the three Reiki II symbols, hand positions and the attunement process. Following Dr. Usui's request to develop the system of Reiki, Dr. Hayashi created a complex hand position system based on his experience as a medical doctor and from his experience working in his Reiki clinic. He also further developed the attunement process and may have been the one to add the master symbol, although it is possible that the master symbol was added by Mrs. Takatal.
Mrs. Takata developed what she called the foundation treatment which is a simplified version of what she learned from Dr. Hayashi. The foundation treatment consists of 4 hand positions on the abdomen area and 3 or 4 hand positions for the head and a few optional hand potitions on the back. She also decided not to teach most of the techniques (now called Japanese Reiki techniques) she learned from Dr. Hayashi, thus simplifying the system for Westerners. She also added the fee structure previously mentioned. So while the lineage is the same, going back to Dr. Usui, and the 3 symbols from Reiki II are the same as Dr. Usui taught, in many ways, the system of Reiki she taught was different than what Dr. Usui had originally created. The important thing is that her system is effective with the addition of the foundation treatment being her most important contribution to Reiki.
The required waiting periods between classes were added by several of Mrs. Takata's Masters after she passed on. Actually according to Mrs. Yamaguchi who became a Reiki teacher under Dr. Hayashi, Dr. Hayashi taught that Reiki treatments should be given for free. This is why he taught mostly to wealthy students who could afford to practice without charging money. So, while some say payment must be received, we know that this is not a requirement and that it is really up to the practitioner to decide if they want to charge a fee or not for Reiki treatments.
Takata said Reiki is an oral tradition and because of this didn’t allow her students to take notes or to tape record and she had no written handouts; neither did she write anything about how Reiki is to be taught. (We now know she did teach one class in June, 1975 in which she did give handouts and did allow her students to take notes. See the summer 09 issue of Reiki News Magazine.) Because of this it became difficult to verify exactly how Reiki is to be practiced. This became especially problematic after she passed on.
After Mrs. Takata's transition, a few teachers began making changes in the way they taught Reiki. Most of the changes were beneficial, and included the addition of knowledge and healing skills the teachers had learned from other systems or had acquired from inner guidance. However, some changes were restrictive, making it more difficult for students to progress. Some took the Third Degree and divided it into several small parts, calling each new part a new Degree and charging additional money. Often, the fact that they had modified the Takata system was not mentioned and when their students became teachers, they began teaching what they thought was pure Takata style Reiki and even calling it pure Usui Reiki when in fact it was not. In this way, many varieties of Reiki have developed with some thinking they have the only authentic version of Reiki when actually what they are teaching is a modified form. Much of the information on the web about the history of Usui Reiki and how it is taught and practiced has not been well researched and people are simply publishing anything they have heard without attempting to find the source or check references.