I started a new thread because I put the choke thread off topic with this. Apologies for that. First off I want to state that I am in no way dismissing Shorinji Kempo with pointing out this connection. Actually I think the combination that Doshin So created of goho and juho is very logical and rational. BUT I personally don't like to ignore holes and I believe martial arts should stay 'alive' and constantly critique their own methodologies. Having just attended the Hombu training after the World Taikai, I know I'm bucking the system and the speech that Yuuki So gave. I agreed with a lot of what she said and the goals of Shorinji Kempo to maintain unity, but at the same time the world is changing regarding information availability and the old world of 'martial arts secrets' no longer exists.
Hakko Ryu was founded in 1941, so Doshin So may have learned joint locking waza in Manchuria, but the actually Hakko Ryu connection was later. According to Hakko Ryu Soke Ryuho Okuyama, Doshin So and a Shorinji Kempo 7th Dan are on the scrolls for Hakko Ryu (in Koryu type arts you sign a register for classes - Hakko Ryu isn't Koryu but they kept some of the formality) (http://www.aikidojournal.com/article?articleID=81)
Dismiss his negative assertion about Doshin So and the 'pain' of the technique - so common to hear this type of talk dismissing other 'founders'. Ryuho Okuyama studied Daito Ryu, but focused primarily on the jujutsu component, i.e. primarily kuzushi and joint locking throws and takedowns. He didn't really study the 'Aiki' component. Why he 'founded' Hakko Ryu (the style of eighth light) is he was also a shiatsu and Chinese medicine practitioner and he added 'Seiho' and pressure point attacks to his jujutsu (hint.. see the Shorinji connection?) hence in his mind making it a unique system.
I've crossed trained with Daito Ryu, A lot of the Shorinji Kempo waza are pretty much identical the way they are trained. What I see as a 'hole' in Shorinji Kempo is that there isn't a consistent method (that I've seen so far) for training transitions from Goho to Juho. In traditional CMA this is referred to as 'sticky hands' and involves some body methods (Shen-fa).