The ninja heritage of the Bujinkan is from Iga province, so this is a great article written by Sean Askew as a Facebook Post posted on his personal FB page. Visit his website/blog for more: bkrbudo.com

"Evidence for the resiliency of the Iga-no-mono shinobi warriors
Most ninjutsu history enthusiasts are aware that the Iga province was conquered by Oda Nobunaga in 1581 CE after a failed attempt in 1579 CE by his son Oda Nobukatsu. This battle, in Japanese, is called Tensho Iga no Ran. But did you know the men of Iga made a bit of a comeback???
Oda Nobunaga's large army of approximately 42,000 men attacked the Iga warriors, totaling 10,000 men at most. When the Oda forces advanced, they burned down castles, shrines, and temples. The most significant battles were the siege of Hijiyama Castle (the headquarters for the northern Iga forces defended by Momota Toubei and Toda Zairoku) and the siege of Kashiwara Castle in the south (defended by Momochi Tanba Yasumitsu, headmaster of Gyokko and Togakure Ninpo). When Hijiyama castle was about to be lost, Momota Toubei and Toda Zairoku escaped at night and fell back to Kashiwara to support Momochi.
Vastly outnumbered, the Iga forces quickly surrender at Kashiwara Castle on October 8, 1581 CE.
But nearly all the major Iga shinobi commanders, including Momochi, Momota and Toda, seem to have escaped during the night before the surrender. Large scale Iga resistance ended and control of the Iga province was handed over to Oda Nobunaga's son, Nobukatsu. Fortunately, as you will see below, the Iga-no-mono and their secretive shinobi would live on to fight another day.
In June of 1582 CE Oda Nobunaga committed suicide after being surprise attacked by Akechi Mitsuhide at Honnoji temple. Immediately upon receiving this information, the Iga-no-mono rose up from the various places they had been hiding in. The military chronicle, Seishu Gunki (勢州軍記), describes this as the "Iga Province Dust Uprising" 「伊賀国一挨蜂起」
The Iga-no-mono quickly took back Fukuchi Castle at Tsuge, attacked Oda commanders Fukuchi Iyo and Ikejiri, driving them out of Iga and back to Ise. Sawa Rokuro (沢六郎), Akiyama Ukon (秋山右近), Yoshino Miyauchi (芳野宮内) and others from Yamato were dispatched to suppress the uprising against the guardian of Iga (伊賀守護) Nikki Yubai (仁木友梅) at Heiraku-ji Temple in the heart of Iga.
In a sense, it was this Nikki Yubai that set off the chain of events into action that led to Oda’s invasion of Iga. After officially being appointed guardian of Iga, with Oda Nobunaga’s approval and support, he was invited by the countrymen of Iga to come to Iga from Eshu. After staying in Sanda for a while, he entered Iga province and settled at Heirakuji Temple (平楽寺) in Ueno. He ruled as the lord of Iga, but the countrymen came to despise him for his policies. A fissure gradually arose between them and in 1577 CE, he was exiled to Shigaraki in Koka after a confrontation with Momota Toubei over a Buddhist statue.
This event in turn infuriated Oda Nobukatsu causing him to underestimate the warriors of Iga and fail miserably in his attempt to invade the province in 1579 CE. This embarrassment to the Oda family caused daddy, Nobunaga, to invade a second time in 1581 CE, this time they would not lose.
In the above mentioned Seishu Gunki we find the following entry about Hattori Hanzo and the Kuki family;
…Also, Tokugawa Ieyasu added Hattori Hanzo and his 100-man musketeer units to his forces. In total, the forces of the Iga/Ise army numbered more than 30,000 men. Takigawa had long been taking hostages from the southern samurai families (to ensure loyalty). However, Tamaru Nakatsugu Shosuke (田丸中務少輔), Kuki Osumi no Kami (九鬼大隅守), Sawa Genrokuro (澤源六郎), Akiyama Ukon Shogen (秋山右近将監), and Yoshino Miyauchi Shosuke (芳野宮内少輔), at the advice of Toyotomi Hideyoshi, plotted a rebellion and became allies of the Hashiba clan (羽柴家). Oda Uenosuke Nobukane (織田上野介信包)　also sided with Hideyoshi…
勢州軍記
巻十一　信雄兵乱
松島篭城の事
…また家康が服部半蔵に鉄砲百人を添えこれに加勢した。そのほか伊賀伊勢の軍合わせて三〇〇〇余である。瀧川はかねてから南方の諸侍から人質を取っていた。しかし田丸中務少輔、九鬼大隅守、澤源六郎、秋山右近将監、芳野宮内少輔らは秀吉の勧めによって謀反を企て羽柴家の味方になったということだ。また織田上野介信包も秀吉卿の一味であった…
I find this to be clear and compelling enough evidence to demonstrate that ninjutsu was not squashed out by Oda Nobunaga and his invading forces. It seems to be quite the contrary. It also shows that by the end of the Sengoku Period the warriors of Iga were advanced marksmen and were held in high regard for this. More so than their skills in invisibility and magic. As soon as Nobunaga was dead the shinobi of Iga quickly sided with Tokugawa Ieyasu to form his personal bodyguard and sharpshooter unit. Ieyasu and his family in Mikawa province had been long-time benefactors of both Iga no mono and Koka no mono, so it was a natural transition.
The next question that pops up in my head is, what would they have done had Oda Nobunaga not died at Honnoji? Would they have still risen up and try to take Iga back, or would they have stayed in hiding and make a new start elsewhere?
The search continues...
Ninpo Ichizoku!!!
Sean Askew – Dōtō 導冬
Bujinkan Kokusai Renkoumyo
August 23, 2020"

Great article on the Togakure Ryu, written by Sean Askew and posted on Facebook:

"Just how badass was the Togakure Ryū???

Today I received an email asking me “I don’t see much historical information available regarding the Togakure Ryū, in your opinion just how badass do you think they really were???”

This is a great question; it requires a lot of explanation.

First, keep in mind that the actions of the shinobi were never meant to be made public, so it is likely that 95% of the ninja’s history will never be known. But we can get good glimpses from reliable source texts as to the types of missions they were involved in.

In the case of the Togakure Ryū, during the 1500’s the headmasters of the lineage were of the Momochi family.
According to Toda Shinryuken’s oral traditions, there were no less than ten Momochi family members that acted as Grandmasters of the Togakure Ryū. They were considered, along with the Hattori family and the Fujibayashi family, to be the supreme commanders of the Iga-shu shinobi. Today we often refer to these families as Jōnin (上忍). Therefore, in my humble opinion, any actions that were carried out by the Momochi family and their supporters would have been executed by Togakure Ryū shinobi.

On top of this there is plenty of evidence to show that the Fujibayashi family were from Togakure village and that their ninjutsu was of Togakure origins.

For one final nail, we also know that the Hattori family, Momochi family and the Fujibayashi family had extremely close family connections, including intermarrying, adopting each other’s children, etc.
So, it is likely that the differences between these three families’ styles of ninjutsu would not be that different. Rather, it is likely they shared many similarities.

With keeping all of this in mind I would like to introduce an entry in a historical record that shows just how extremely effective these ninja families were.

In the chronicles of Ozuki Tokimoto (小槻時元記), there is an entry for February 15, 1502, that says when the local rulers of Iga tried to secure their control over the peasants of the region for their idleness, the peasants asked for help from the yamabushi in Kyoto on Atago Mountain. Soon after, dozens of yamabushi (mountain priests) from Atago, accompanied by about 400 men, invaded Iga Province.

However, the Iga-shu 伊賀衆 (the shinobi) rushed into the Yamabushi camp at night and defeated them without having a single formal battle, leaving only a dozen or so people to return to Kyoto. This was described as an extremely "strange occurrence” because the Iga people must have been well-trained and used guerrilla warfare methods such as surprise attacks and distractions. It must be so as they easily defeated the Yamabushi, who were known to have been skilled in battle, with less than 20 men.

So, in summary, I believe that as this was 1502, the Momochi family were most likely directly involved in these actions. Being that the attack was coming from Kyoto it would have been the Momochi and the Kami-Hattori clans that they would encounter first. So, if the Momochi family was involved, I think it is safe to say that it was the Togakure Ryū.
To answer his question…the Togakure Ryū were more badass than 400 battle hardened men from Atago Mountain, where the men there were known to be masters of the martial arts. This is probably why they were even able to defeat Oda Nobuo's army during the early part of the Tensho-Iga War.

Ninpō Ichizoku!!!
Sean Askew – 導冬 - Dōtō"

- Facebook post by Sean Askew, August 18, 2021

This is going to be a controversial blog post by Sean Askew for some Ninja history enthusiasts, but very informative and likely bringing new information to light that most people do not know about. I'm including a teaser of the beginning of the blog, click on the link and go read the full thing on his website:

Blog post by Sean Askew:
"Is the Bansenshukai even worth the paper it is written on??? Of course, I’m kidding but only partially…
Credibility is defined as the quality of being trusted. In literature, having a credible text means that the information therein is reputable and a trusted source for those looking for information on the subject. In this post, I will go over why the Bansenshukai and possibly other famous ninjutsu texts are not credible, or at least not completely reliable.
When a document is said to be a secret one, passed down only within the clans of the shinobi, or “ninja” for the lay people out there, you would expect it to be accurate. You would expect it to have credibility, right?! After all, from the early 1600’s until the late 1860’s the shinobi families that served the Tokugawa shogun provided a nationwide network of spies, assassins, sharpshooters, etc.
Taken from Wikipedia… “The Bansenshukai was compiled by Fujibayashi Yasutake in 1676, in the early years of the Tokugawa shogunate, to preserve the knowledge that had been developed during the near-constant military conflict from the Ōnin War until the end of the Siege of Osaka almost 150 years later. As well as information on military strategy and weapons, it has sections on the astrological and philosophical beliefs of the times, and along with the Shōninki of 1681 and the Ninpiden of 1560 make up the three major sources of direct information about this shadowy profession.”
So, if this document was meant to preserve secret knowledge for a very specific group of people, the text’s credibility should be considered as of the utmost importance. Should it not?
But, within the Bansenshukai, as with the other documents mentioned, there are several items that are discussed where I am highly skeptical of its validity or accuracy. Of course, most of the document is filled with logical things that make sense, but at times there are things that are just not right..."
​Finish the article on his blog: BKRBudo.com