Ed is correct about the Hohan Soken lineage, but I would like to add a little if I may.
Sensei Soken went to Argentina in 1928 and returned to Okinawa in 1952. In Argentina he had several students. One of them happens to be my teacher, Dr. Henry Inoue(Born to Okinawan parents in Argentina, using an English 1st name for teaching medicine in the US). Dr. Inoue was a long time student of Soken both in Argentina(not the only one,many are still there) and Okinawa.
*** It is very important to note that Sensei Soken ALWAYS maintained that Matsumura Seito WAS NOT the only true/legitimate Shorin Ryu. It is merely his Grandfathers style passed in the family*****
Sensei Fusei Kise is probably the best known Matsumura Seito practioner. He has a background in Shorinji Ryu and Matsumura Seito. While he is arguably one of the finest Seito practioners, It is important to note that Kenshin Kan(His current teaching) is not
Sensei Kise is an excellent practioner and teacher, and one of the toughest men I have ever known, but he has not taught O'Sensei Sokens art for many,many years.
Again Ed is correct in saying that since the 1950's (having returned to Okinawa) Sensei Soken has had some good and some bad students. And the in vogue trend is to have claimed to have trained with Sensei Soken. Matsumura Seito has become quite fashionable over the last few years.
I'll go on record here at FA. I was 10 years old living in the Mid-west in the US when O'Sensei Soken died. There it is. If in a few years I become a 10th dan Soke and claim to be the heir to MSSR(Given the right by O'Sensei Soken)a good research hound like Ed can lump me in with Frank Dux and Ashida Kim
So here is the long and short of it, and kinda trying to get back on track. Sensei Soken has trained some less than credible characters(for as great as he was, he too was capable of being duped). Some truly remarkable Martial Artists were also trained by Soken. They took his influence and have done their own thing(nothing wrong with that). And men in women who have trained in the Bushi Matsumura>>>Hohan Soken lineage have been good and bad and produced good and bad.
Am I proud to be able to trace my lineage through Bushi Matsumura and farther? Of course I am. I would be equally proud to trace my lineage through Miyagi,Higaoshionna, Ru Ru Ko, or any of a number of others.
Rememberin all the while that my lineage is not the only one that has had a dramatic and positive effect on the history and future of Okinawan martial arts.