Hello, Zendokan, thanks for your reply. I'd like to try to respond to some of your points if I might.
I agree with what you say on the fact that Choi was no "official" student of Daito-Ryu. And the statements that connect Choi to the grandmaster at that time of Daito-Ryu aren't sure if Choi was an adopted son or a servent. But he lived for 31 years with that grandmaster, this we now.
Actually, we don't know those things.
We know that Choi spent about 30 years in Japan. We know beyond any doubt that he learned a sophisticated form of Jujutsu that definitely has aiki techniques.
We know, from Choi's accounts to at least one of his long-time direct students, that Choi always maintained that while he was in Japan he learned Daito-ryu directly from Takeda Sokaku. We know further that he maintained that he taught exactly what he learned in Japan - without modification.
We
don't know for a fact if Takeda actually taught him.
It is next to impossible that he was considered an "adopted", or surrogate, son of Takeda (by the way, the source of that story is highly suspect). He might have been Takeda's servant, but with the evidence available to us today, we can neither prove nor refute that hypothesis.
But I saw in your profile that you did Hapkido and Aiki Ju Jutsu.
Yes sir, that's right.
I think you would agree with me that there excist alot of techniques of which you could say that they are unique to Daito-Ryu and his offspring styles. A sort of style fingerprint.
Yes.
Well you can find that fingerprint from Daito-Ryu in Hakko-Ryu, Aikido and Hapkido... So the fingerprint proofs that Daito-Ryu is the ancestor-style of Hapkido, ofcourse Hapkido is different from Daito-Ryu thru evolution and adaption (Koreans are not Japanse, militairy use in an effective war, expotior to other korean systems, etc...), but the fingerprint techniques stayed.
With regard to Hakko-ryu and Aikido, there is no doubt about the link to Daito-ryu.
With regard to Hapkido, to repeat, we simply can't prove it.
I'd be elated to find proof that Choi learned Daito-ryu. I can tell you from first-hand experience that if you are fortunate enough to be able to find both a school that teaches the Jujutsu-based art that Choi taught when he returned to Korea (there aren't many - most teach the expanded art, with a strong focus on kicking, that can be traced back to Ji Han Jae), and a legitimate Daito-ryu school (of which there are very few in the US), and you train for a while in both, you will most likely conclude that Choi did learn Daito-ryu somehow.
But, as confounding as it is, we still can't prove it. Nor do we know who really taught him during all of those years in Japan.
Again, thanks for your reply.
All the best, Howard