One just does not train with someone for 21 years as their primary instructor and then poof they are or were not their teacher! That probably is the only thing that bother's me about Tanemura Sensei. (my personal opinion) However, their family dispute is really none of our business and is an old dead horse. Still regardless of that I really like what he has done with the Genbukan and has managed to turn out some great practitioner's. With Manaka Sensei this issue is not a problem as he acknowledges Hatsumi Sensei as his primary teacher. He was just ready to move on and go his own way. Nothing wrong with that and for some people it is important to grow as a martial practitioner.
I absolutely love what Manaka Sensei has done with the Jinenkan. Tanemura Sensei, Manaka Sensei and several others are or were at a level where they could easily move on and found their own system. There is nothing wrong with this, it is natural and for some practitioner's it is important for their own growth. As an instructor one should never try to curtail someone else's growth. The key as an instructor is to recognize this and when someone is at a level to move on we should help them.
However, that is hard for some people! Always has and always will be. Still in the end "the source" for the Takamatsuden arts is Hatsumi Sensei as designated by Takamatsu.
That is just the way it is.
If we were to draw up a proper hierarchial lineage of the three Takamatsuden arts and the Kans it would primarily look like this:
..........Bujinkan
..................↙ ↘
Genbukan Jinenkan
Of course each instructor had outside influences as well!
Or a teacher chart:
........Takamatsu
...................↓
.........Hatsumi
.................↙ ↘
Tanemura Manaka
Of course we could insert a whole lot of other people in this as well! I know these charts do not jive with some people but.....
they are accurate!
This in no way implies that any one of these systems is inferior to the others. Slight differences yes but the similarities abound regardless of outside influences! I like the quality control in the Genbukan and the Jinenkan but can understand the impossibility of this in the Bujinkan. Nor does restrictiveness jive with how Hatsumi Sensei does things. Having been around all of the highest level practitioners I like being closer to "the source" and at the highest level in Japan the movement in the Bujinkan. (that is also having experience with high level Genbukan and Jinenkan members)
Yet, that is just my opinion and nothing more!
I would also add that to this point
no westerner who has broken away and found their own system had enough experience or knowledge for their new system to be included in the Takmatsuden lineage as a Takamatsuden art. This is because of their lack of knowledge, skill, ability, etc. While they certainly may be
some what Takamatsuden derived they certainly lack what Tanemura Sensei and Manaka Sensei had at the time of their departure. (skill and knowledge) This of course does not even take into effect Menkyo Kaiden. (both Tanemura Sensei and Manaka Sensei had this) This of course is very important in Japanese Martial Arts to be included in the Takamatsuden lineage. So they really do not get to sit at the table. There are of course some westerners who now have the ability at least in the Bujinkan. (a very small group) Whether they have Menkyo Kaiden or not is between them and Hatsumi Sensei but would be important for them to be included in the Takamatsuden lineage chart and to form their own Kan. I frankly do not know about the Genbukan or Jinenakan in this regard.
In the Takamatsuden Arts the gold standards are the Bujinkan, Genbukan and Jinenkan. My preference is the Bujinkan.
Other people might have another preference! As I stated earlier based on other people's recommendation of Luke Molitor that I personally know he would be a good person to check out and see if his teaching would work for the OP. Still he should check out everyone else on his list and find the right fit for him!
