We've been accused of unreasonable prejudice against the popular "ninjutsu"-derived arts. Simply put, it is our opinion that modern-day ninjutsu and ninjutsu-derived arts are not koryu bujutsu. They are not based on a continuous transmission of technique and culture. Koryu.com covers koryu bujutsu. That doesn't mean that arts we don't cover are not worthwhile. We just don't cover them. Given that this is my site, I think that is my perogative.
Let me say this again, since it seems some people don't understand. Koryu.com does not cover ninjutsu! The art and those derived from it do not fall into our definition of the koryu bujutsu. Period. If you want to define the koryu differently, that's fine. Just don't ask us to change our definition, which is based on considerable first-hand experience and decades of research in Japanese source material. Please do not trouble yourself to write us to try and convince us to change our minds. It will not work.
We have made every effort to be as low-key as possible on the issue of "Is ninjutsu koryu?" We do not stress or advertise our position. That's because we sincerely believe that if your training is working for you then it is none of our business. However, if you come to us and ask whether we consider ninjutsu or the Bujinkan-derived arts to be koryu--well, we can only provide our honest opinion.
Please, please, please don't waste your time or ours. We really are familiar with the material relating to this issue; unless you happen to be a Japanese scholar who delves into ancient makimono, you won't turn up something we haven't seen and considered. Again, just because we don't share the same opinion doesn't mean that we are not all doing useful and good training. Yoroshiku onegaishimasu. I really appreciate your consideration!