What is the origin of Shotokai?
Before I answer that question, I would like to explain the origin of the word Shotokai.
Shotokai is the organization behind Gichin Funakoshi's method. "Kai" means school. The senior students of Master Funakoshi established an association with the friendly objective of helping the master's friends and the practice of Karate. The Dojo was called Shotokan (kan=house). Master Funakoshi called his method Karate-do, but it was very easy to confuse the name of his Dojo with the name of his method. His student came from the Shotokan....
Shotokai posesses the Main Dojo (the Shotokan) and the house of Master Funakoshi, which have both been restored. The Head of Shotokai was Shigeru Egami. In the face of Karate's evolution, considering the fact that "Shotokan" [sports karate] was straying further and further away from Master Gichin Funakoshi's Karate, he chose a different position.
When Master Funakoshi arrived in Japan (from Okinawa) he was more than 50 years old and his students thought he executed his movements in a relaxed way due to his age. This relaxation is, in fact, fundamental. It is only nowadays that all is done with strength and this is actually a true contradiction.
Furthermore the evolution of competition in Karate is opposed to Karate-do ettiquette. Competition has resulted in the loss of many things in Karate-do.... but possibly, we may not have the right to criticize considering that we practiced it and now we have abandoned it! [Murakami Sensei originally trained in sports karate]. Competition, today, is not the result of practice, rather the result of practice for competition... and this is very different. A specific preparation is not pure practice!
Anyway, I believe that comparing Shotokai with other styles is not possible, because it truly is something completely different. It does not have competition as the objective, rather the liberation of body and spirit.