History of Ninjutsu: Special Forces Other Than Ninjas

忍者以外の特殊部隊 Ninja igai no tokushu butai (Special Forces Other Than Ninjas) (Page 110-116) from the book 忍者 Ninja. Written by 山北 篤著 Atsushi Yamakita.

Special Forces Other Than Ninjas

In the modern battlefield, besides the regular forces that clash head-on, various people with sundry skills do work. But before the Warring States period, regular forces would handle, on the spot and as needed, the matters that special forces ought to perform—such as the guerrilla warfare of Minamoto no Yoshitsune (源義経) himself—or make do with temporary hires. The Warring States era, unlike previous times, was the first age wherein, besides regular forces, specialist units with respective special skills were established.

Besides ninjas, sundry special forces existed. In particular, the establishment of sappers as a specialist unit held exceeding great significance in military terms.

黒川金山衆 Kurokawa Kanayama-shū

That Takeda Shingen (武田信玄, 1521–73) of Kai (present-day Yamanashi Prefecture) was strong was not solely because Shingen was a famed general. That he possessed in his domain a multitude of gold mines, and could employ the vast gold produced thence as military funds, greatly availed in forging a puissant army.

Kai proper, being in the mountains with scant rice production, was a poor land; yet that he could sustain a puissant army was thanks to the gold mines. Those gold mines, from around the time of Shingen’s death, abruptly declined in output, and in the era of the next generation’s Katsuyori (武田勝頼, 1546–82), were as if abandoned mines. That Takeda Katsuyori met defeat was doubtless partly due to his own qualities, but the influence of military fund shortages—a matter not his own fault—must have been great.

Now, Shingen greatly exploited this Kanayama-shū in military affairs as well. Among the sundry gold mines, the one most used militarily was the Kurokawa Kanayama-shū. The reason being, the Kurokawa gold mine of that time flourished exceedingly, and around the mine formed a town called Kurokawa Senken, of a thousand-odd houses. Thus, even if somewhat many were drawn forth, it would not hinder the mine’s operations; perchance for that they were chosen.

Shingen would have them follow to the battlefield, and perform camp construction or gold-digging assaults.

Camp construction ranged diversely from arraying camps for lodging (stretching the main camp’s pavilions, or setting guard ropes around the encampment) to field fortification before the foe (making impromptu defensive positions), but modern we can well imagine it.

Gold-digging assault is one siege tactic begun from the Northern and Southern Courts period onward. It hath the methods of having sappers dig tunnels from without the castle to make voids beneath the walls and such to collapse them, or dig tunnels to water sources to dry up wells, or bore directly into the castle interior to send in assault teams.

Such works requiring advanced civil engineering skills were impossible for common soldiers. Thus, the Kanayama-shū, being mining engineers, would follow to the army.

In military tales, ’tis said Shingen first used the Kurokawa Kanayama-shū in the siege of Matsuzaki Castle, held by Uesugi Kenshin in present-day Saitama Prefecture, in Eiraku 4 (1561). The Hōjō clan had come to assail Matsuyama Castle, but Takeda Shingen, allied, also joined the castle assault. Yet Matsuyama Castle was a stout fortress, with wells within, and seemed not like to fall easily. And if time passed, Kenshin would come to the aid from Echigo (present-day Niigata Prefecture). Thus, Shingen resolved on gold-digging assault, it saith.

But this is the account of a military tale, and dubious. For the gold-digging assault was Shingen’s secret weapon; even in alliance, ’twould not do to use it for the Hōjō house. For in breaking alliance to war, it would show one’s hand.

As a record that remaineth, the gold-digging assault was in Kōtai 2 (1571), in the siege of Kirigayama in Sagami Province (present-day Kanagawa Prefecture). Takeda Shingen, surrounding Hōjō Ujinaga’s defending Ushizawa Castle, mobilized the Kanayama-shū to collapse the outer bailey and take Ushizawa Castle. To reward this merit, the inbanjō given to the famed house of the Kurokawa Kanayama-shū, Tanabe Shirōzaemon, remaineth even now.

Now, the Kōsaka Jūnai introduced in the second chapter hath a theory that he was of this Kurokawa Kanayama-shū origin. If so, perchance the Kurokawa Kanayama-shū were ninjas. In truth, as ninjas and yamabushi have deep ties, so too the Kanayama-shū, who move through the mountains, have deep ties with yamabushi. That the Kurokawa Kanayama-shū bore one wing of Shingen’s ninja bands would be no whit strange.

穴太衆 Anata-shū

Anata (also Anao) is an ancient place-name in Ōmi Province (present-day within Ōtsu City, Shiga Prefecture), wherein dwelt folk who processed stone materials like stone pagodas, stone Buddhas, stone walls, and paving stones for Hiei-zan Enryaku-ji. Anciently, they are said to have been migrants from Baekje.

But their lives underwent fundamental change by one man. Oda Nobunaga.

Nobunaga burned Hiei-zan and permitted no rebuilding. Thus, the Anata-shū lost their greatest patron, and their livelihood was threatened.

But to the straitened Anata-shū, ’twas also Nobunaga who extended a hand. Knowing they excelled in stoneworking, Nobunaga commanded them to build the walls for the new Azuchi Castle. Construction of Azuchi began in Tenshō 4 (1576); upon completion, the stone walls of the tenshu-kaku stood over twelve ken (22m), a height like a five-story building—a vast stone wall.

This majesty is said to have captivated even the sundry daimyo who came from lands afar to pay respects to Nobunaga. Even after Nobunaga’s death, they would commission the Anata-shū for their own castle constructions. Thus, the Anata-shū spread nationwide, and in sundry lands’ Anata-gai, each with their own Anata-gashira, vied in rivalry.

Even in the Edo era, as the bakufu encouraged castle repairs, daimyo needed able stonemasons and came to keep the Anata-shū on high stipends. Such Anata-gashira as Tōba Suruga, who served the bakufu, took 500 koku, far higher-paid than common retainers.

黒鍬衆 Kurokuwa-shū

Kurokuwa meaneth iron spades, and thence came to denote the laborers who perform civil works therewith.

In the Warring States era, those hired by daimyo to make earthen ramparts or roads came to be called kurokuwa-shū. Moreover, they handled logistics like supply transport, and conveyance of the dead and wounded. Further, they grew capable even of works like enemy position or fortress sabotage, such as modern combat engineers perform.

In particular, the kurokuwa-shū of Chita in Owari (present-day Chita Peninsula, Aichi Prefecture) were famed. Those kurokuwa-shū under Tokugawa Ieyasu’s command continued, even in the Tokugawa era, to handle the Edo Castle repairs.

But their status was low; they were not deemed samurai, nor permitted surnames.

The Neglect of Sappers and Logistics

In the Warring States era yet, in the Tokugawa era, sappers and logistics were exceedingly slighted, and those in charge had low status.

This was, one cause being that Ieyasu excelled in field battles and was poor at sieges. Though allied with Nobunaga and Hideyoshi, Ieyasu seemeth not to have learned Nobunaga’s logistics system or Hideyoshi’s sapper command.

Moreover, to make an era of peace like the Edo period, an advanced logistics system or excellent siege system was, in its very existence, a trouble. For these are systems for foreign expeditions, and for the Tokugawa bakufu, knowledge ill-convenient. Of course, there were folk who sought to preserve such know-how, but if long unused, that knowledge rusteth and is forgotten.

For such reasons, this knowledge and the folk who oversaw it came to be coldly treated.

The evil custom of not valuing sappers or logistics was carried over even to the modernized Japanese army thereafter, and became one cause of the great defeat in the Second Great War.

---