Please understand that I do not encourage or enjoy the use or carrying of weapons and I urge you to consult and follow all [Federal/State/Provincial/Municipal] laws and regulations before you even consider the responsibility.
The historic Ninja, more accurately Shinobi, Shinobi-no-mono, or Kusa were masters of many different skills. Most notably escape and evasion. Escaping hostile situations was a small part of a Shinobi’s skill set though, rather escaping anyones awareness was the greatest feats a Ninja could achieve. So much so, there is much debate regarding the true history of those who later came to be referred to broadly as Ninja.
Why this interests me is in part their ability to utilize common items and hide within them lethal weapons. This, perhaps amongst any other martial system sets the Ninja apart. Their ability to create and master a myriad of weapons that although were devastating, were hidden in plain sight.
From the article below, it seems that the Shinobi did not possess this quality alone. We may have to give a tip of our hats to acknowledge one of the first masters of silent warfare. For more examples of more modern hidden weapons follow the link provided: http://www.unfinishedman.com/gun-porn-101-disguised-guns/
A case that inconspicuously unfolds into a pistol; a Zippo lighter that carries something a bit hotter than a flame; a whip-gun that ‘cracks’ twice.
The second and more poignant aspect that I have adopted is the versatility of their tools. When setting out on long expeditions which must be conducted above the suspicion of those around you and perhaps unsupported, you cannot storm off into battle with rifles slung, and swords-a-ready. This forced the Shinobi to become not only ingenious in their problem solving, but extremely creative in their design. The result of these two characteristics were tools that could solve many problems in many different situations. Swords that were ladders. Ropes that were employed not only to climb but also disable, secure, and kill.
The famously recognized ninja star which is always viewed being thrown, is actually only the exhibition of one set of techniques utilized with a specific type of Shuriken. The idea being that any technique should be performed with a myriad of tools in your hands and you should not be hindered by your equipment. Perhaps not in every specific case, but for a large amount, you can do a hip throw bare-handed, or with the aid of a staff or Yari, or maybe with a rifle. Perhaps that machine you carry is more than for punching holes and being used as a blunt instrument and can instead assist you in performing much more effective movements.
The Shinobi Nawa, or Ninja Rope: Consisted of a long piece of rope with an iron ring on one end, and a blade on the opposite. It can be thrown using the ring as a counter weight, or used in an altercation to tie up your enemy
The lesson to be taken then is not all is that it appears to be. As such we should seek to employ things for as many purposes as we can that are beyond their common usage. In this way, we may begin to select our gear perhaps not by its one greatest quality, but because it serves the greatest amount of purposes very well. The Ninjato [ A shorter, straight sword used to parry and poke in and around the larger, more curved swords of the Samurai] utilized by Ninjas were not the best quality and did not have the sharpest blades, but they developed a method and a tool to deal with adversaries who were better equipped and usually in larger numbers. Their needs drove their selection of tools and training and there was no disillusionment about the fact that their survival depended on these choices.
Masaaki Hatsumi, the 34th Grandmaster of the Togakure-Ryu demonstrates that a mask serves not only to intimidate opponents, but also to strike at them and block with as well. Tools like this mask aided in developing the image of Ninjas as Oni or Demon warriors.
Know your task, and plan accordingly.