Hello, I know that Shotokan and Wado-ryu share a couple of katas. As their moves are a bit different, I like to know if Wado-ryu is preserving the katas as they were in Shotokan when Otsuka left Funakoshi about 1928, or if he developed the katas further, or maybe both, or if he even took older (Shotokan) versions or versions from Mabuni (so maybe they are not Shotokan based katas after all).
Bittmann writes that Otsuka left due to differences, but are there more details about that part of history? From a McCarthy interview I know that he developed the gohon/sanbon/ippon-kumite during the Shotokan times, so he was involved in the creative process. I deduce he wanted something in Karate that the Shotokan people didn't want and I bet he implemented it in Wado-ryu. What is it? Or was it a personal conflict, e.g. with Funakoshi's son? (a trainer of mine hinted this once).
Are there book sources about those backgrounds and ideas going on at that time?
I found some information in the book Shotokan Mysteries by Yokota and some information in other sources, like the english wikipedia article about Otsuka (too bad the sources this article quotes are not all available via internet, but that one is: https://wado.ca/grand.html, though it does not quote its own sources). As this post has lots of views but no answer, I want to share the information I have now:
Otsuka trained around 1922 - 1930 with Funakoshi (btw: Gigo joined 1923 at age 17, until 1945), was assistant trainer since 1928, Motobu arrived 1921, Mabuni arrived 1928-29 which were the earliest times to train with them, then according to the Mysteries book Otsuka had his own dojo in 1931 (or 1934 according to the linked article), meaning he was independent by then. Wado-ryu then was recognized as a Karate style in 1934.
The linked article states that "it was with Mabuni that he clarified the Pinan katas" (a strange wording imo; does it imply Mabuni had additional or better information?) and "Otsuka worked with Motobu on the Naihanchi kata" (that makes sense, he was basically the Naihanchi guy :-) And on the time frame it happend after Otsuka met Funakoshi; I wonder if Motobu's special visit to Funakoshi's dojo had to do with it).
The sources conclude that kata changes like kokutsu-dachi & yoko-geri keage & uraken and slow start of Heian yondan appeared after 1930 in Shotokan, that the changes were "criticized by many Okinawan masters of that time" (man, I want these sources...) and more changes happened from 1949 with the JKA. The Mysteries book also describes that the university students and Otsuka requested a training syllabus of kumite and the linked article dates his Jiyu-kumite studies at 1929. The book also finds the Kendo influences to kihon kumite noteworthy, just like McCarthy and one of Iain's podcasts or videos.
The linked article says that the differences came up due to the lack of realistic fighting situations (Goshin) and Jiyu-kumite, but also "the performance of kata" which could imply he left not before but when or maybe because Shotokan changed in the wrong places.
I think that answers the questions I had, with a certain likelihood. My request to everyone who ever writes about Karate: please quote sources. History is a mess and we also suffer from the anti-pattern of disappearing books and a lot of hearsay.