Access all areas...
One of the skills of the ninja was the ability to get into fortified structures, guarded areas, and places that were generally regarded as secure. There were many different tactics employed and we will look at some of these in this blog.
Now, despite the Hollywood mythos, ninja couldn't disappear in shadowy corners, transform or vanish in a puff of smoke. To approach this from a place called reality there are several tactics that can be employed. The first is the most practical - have the ninja employed by the owners of the target area as security or in any role that gains access. Janitorial is one of the more useful roles as there is access to many sensitive areas, and people of influence rarely pay attention to those employed in this role. As technologies have developed, this may be more of a challenge as background checks become more extensive, but not insurmountable.
So, if not employed directly, what next? Well one of the traditional skills used was Hensojutsu, the art of disguise. It was also known as 'Shichi Ho De' or seven ways of going. While not literally seven disguises the most common ones were priest, samurai, merchant, craftsman, performer, puppeteer and farmer. Suggested modern versions of these are below.
Or, another option would be the use of latex mask - not for up close work but a useful one for quick changes after covert observations. But, recent studies have shown that these masks can be fairly convincing and is another way of gaining access.
So, the use of disguise is an option. After that, well we start to look at other ways to enter at building or site. So ninjutsu also includes the use of camouflage and concealment for its movement - known as Intonjutsu. This involves the use of natural cover, such as long grass, foliage, rocks and buildings. It also involves being able to move quietly. Its important to differentiate between quiet and stealthy movement. It is not easy to step absolutely silently, especially with modern rubber, plastic and man-made footwear soles. So the trick is be more quiet than your surroundings and the background noise. Or, to put it simpler, only move when someone or something else makes a noise.
Then we are looking at ways of opening closed doors. In the times of the ninja, locks were few and far between and most common were simple dead-bolt type that could be manipulated with thin blades, wedges and anchors. Obviously that is not the case now, so regard should be made to everything from simple lock picking to disarming complex alarms - maybe with codes from inside sources.
This is also where skills in ShoTen - the ninja version of parkour - would also start to come in. Ninja would train in climbing walls, exterior and interior, working through crawl spaces in ceilings, being able to cross obstacles quickly and efficiently. It also included the use of the kaginawa (grappling hook and rope), shuko (for wooden structures and trees), kunai as an anchor point etc. The point was always to cross the obstacle as quietly and concealed as possible. So there were no backflips, somersaults etc involved.
As can be seen, ninjutsu is much more than throwing stars and turtles. One of the key attributes for students of ninjutsu is flexibility, to enable adaptive movement and attitudes. This will all enable endurance and survival when needed.
Sometimes though, the best approach is just walk as if you are meant to be there. Self confidence can deter enquiries as well as any disguise...