Seisan is a very old kata, and it one of the few with obvious Chinese origin. It is practised in every lineage of uechi-ryu/pangai noon and goju-ryu. Although it is usually considered to belong to these styles, it is (probably) the only kata to exist across all Okinawan styles with only minor differences.

A shorin ryu variation of the kata exists, but it is not included in most lineages. what would be the most plausible reason to explain this? What shorin-ryu lineage has seisan and who might be the source of the shorin-ryu variant?

Well i'm a Goju Practitioner.

But from an educated guess, is the number of kata taught across all the branches itself.

So chances are the branches, deemed it not to be important enough to be included.

Now the variant, I think we may have lost who may have made the changes to time. But unless it is Branch specific, and its the creator of said Branch.

That makes sense and it was what the question is about. Back in the early years before there were styles, the kata seisan was already known in the Ryukyu Kingdom. If the kata seisan is that old, it is likely that an expert in martial arts and head of the king’s personal guards would have known this kata.

I'm a Uechi guy, and Seisan is one of our three core kata. According to our history, Kanbun Uechi traveled to the Shaolin temple in Fukien province to study martial arts, and while he was there he earned three Menkyo (teaching licenses): for Sanchin, Seisan, and Sanseiryu. He returned to Okinawa in 1909, and eventually moved to Wakayama Japan in 1924, where he resumed teaching what he first called "PangaiNoon", and later "Uechi-Ryu Karate-Jutsu".

These three kata still form the core of our system. His son (Kanei) and senior students added 5 additional kata to our system to help students better transition between the three core kata. However, when testing for advanced Dan grades (6th dan and up), the tests consist of the three core kata: Sanchin, Seisan, and Sanseiryu.

Seisan is a very old kata, and it one of the few with obvious Chinese origin. It is practised in every lineage of uechi-ryu/pangai noon and goju-ryu. Although it is usually considered to belong to these styles, it is (probably) the only kata to exist across all Okinawan styles with only minor differences.

A shorin ryu variation of the kata exists, but it is not included in most lineages. what would be the most plausible reason to explain this? What shorin-ryu lineage has seisan and who might be the source of the shorin-ryu variant?

As far as I know, my branch of Shorin Ryu doesn't do that kata. Descended from Soken Matsumura, to Soken Hohan, to Kuda Yuichi, eventually to me.

Seisan is a very old kata, and it one of the few with obvious Chinese origin. It is practised in every lineage of uechi-ryu/pangai noon and goju-ryu. Although it is usually considered to belong to these styles, it is (probably) the only kata to exist across all Okinawan styles with only minor differences.

A shorin ryu variation of the kata exists, but it is not included in most lineages. what would be the most plausible reason to explain this? What shorin-ryu lineage has seisan and who might be the source of the shorin-ryu variant?

As far as I know, my branch of Shorin Ryu doesn't do that kata. Descended from Soken Matsumura, to Soken Hohan, to Kuda Yuichi, eventually to me.

Interestingly, my branch of Matsumura Seito does do Seisan. However, my lineage branches differently, from Soken Hohan to Kise Fusei.

Seisan is a very old kata, and it one of the few with obvious Chinese origin. It is practised in every lineage of uechi-ryu/pangai noon and goju-ryu. Although it is usually considered to belong to these styles, it is (probably) the only kata to exist across all Okinawan styles with only minor differences.

A shorin ryu variation of the kata exists, but it is not included in most lineages. what would be the most plausible reason to explain this? What shorin-ryu lineage has seisan and who might be the source of the shorin-ryu variant?

As far as I know, my branch of Shorin Ryu doesn't do that kata. Descended from Soken Matsumura, to Soken Hohan, to Kuda Yuichi, eventually to me.

Interestingly, my branch of Matsumura Seito does do Seisan. However, my lineage branches differently, from Soken Hohan to Kise Fusei.

Essentially the same thing as I do then. Kuda and Kise worked together at first, but as I understand it from several high ranking sensei that left Kise, he was passing out BB's like confetti and changing things quite a bit. My origional sensei studied under Kuda in Okinawa. I received my Shodan from Sensei Kuda.

Essentially the same thing as I do then. Kuda and Kise worked together at first, but as I understand it from several high ranking sensei that left Kise, he was passing out BB's like confetti and changing things quite a bit. My origional sensei studied under Kuda in Okinawa. I received my Shodan from Sensei Kuda.

I also train in the Kise group. From what I understand Kise brought in things that came from his time in Shorinji and that may be where Seisan was mixed in to his version of Matsumura. There are other kata that he brought in.

As far as giving "BB's like confetti", that's over. From what I can tell there was a focused and deliberate effort to make certain those things would not continue in the last five years or so. If I had any issue at all its that the syllabus (for lack of a better term) is too robust for the average person with a normal life (I.E. work, family, other hobbies). I think we may see even more additions now that Master Kise's son has taken over the group. It's a lot of information.

In Shotokan they call Seisan Hangetsu.

I do the Tang Soo Do version of Seisan. Usually the TSD forms are pretty close to the main Japanese styles, due to the derivation from Shotokan. However with this one, I've seen more variations, like in Ryu-Kyu kempo.

I also train in the Kise group. From what I understand Kise brought in things that came from his time in Shorinji and that may be where Seisan was mixed in to his version of Matsumura. There are other kata that he brought in.

That is my understanding as well. In fact, as far as classification goes, my sensei would separate kata into Matsumura kata and Shorinji kata. Seisan, Wansu, and Ananku were Shorinji kata. According to some sources I have found, like old kata lists, from Coffman and Gagne's sites, later Shorinji kata were taught after black belt but were largely Shorinji versions of kata that we had already learned.