Ninjutsu - This is a tough one, most documents or records I found simply point it to being the study of the historical arts of the Ninja covert agents or assassins of feudal Japan. There are several references to the arts of the Ninja and we all know that these skills are suppose to be the nighmare of every enemy. For this I have decided to use text regarding the Ninja and list multiple reference links at the bottom for follow up research.
So-called ninjutsu techniques, in short are the skills of shinobi-no-jutsu and shinobijutsu, which have the aims of ensuring that one's opponent does not know of one's existence, and for which there was special training. The skills required of the ninja has come to be known in modern times as ninjutsu, but it is unlikely they were previously named under a single discipline, but were rather distributed among a variety of covered espionage and survival skills.
The first specialized training began in the mid-15th century, when certain samurai families started to focus on covert warfare, including espionage and assassination. Like the samurai, ninja were born into the profession, where traditions were kept in, and passed down through the family. According to Turnbull, the ninja was trained from childhood, as was also common in samurai families. Outside the expected martial art disciplines, a youth studied survival and scouting techniques, as well as information regarding poisons and explosives. Physical training was also important, which involved long distance runs, climbing, stealth methods of walking and swimming. A certain degree of knowledge regarding common professions was also required if one was expected to take their form in disguise. Some evidence of medical training can be derived from one account, where an Iga ninja provided first-aid to Ii Naomasa, who was injured by gunfire in the Battle of Sekigahara. Here the ninja reportedly gave Naomasa a "black medicine" meant to stop bleeding.
With the fall of the Iga and Kōga clans, daimyos could no longer recruit professional ninja, and were forced to train their own shinobi. The shinobi was considered a real profession, as demonstrated in the bakufu's 1649 law on military service, which declared that only daimyos with an income of over 10,000 koku were allowed to retain shinobi. In the two centuries that followed, a number of ninjutsu manuals were written by descendants of Hattori Hanzō as well as members of the Fujibayashi clan, an offshoot of the Hattori. Major examples include the Ninpiden (1655), the Bansenshukai (1675), and the Shōninki (1681).
The ninja did not always work alone. Teamwork techniques exist: for example, in order to scale a wall, a group of ninja may carry each other on their backs, or provide a human platform to assist an individual in reaching greater heights. The Mikawa Go Fudoki gives an account where a coordinated team of attackers used passwords to communicate. The account also gives a case of deception, where the attackers dressed in the same clothes as the defenders, causing much confusion. When a retreat was needed during the Siege of Osaka, ninja were commanded to fire upon friendly troops from behind, causing the troops to charge backwards in order to attack a perceived enemy. This tactic was used again later on as a method of crowd dispersal.
Most ninjutsu techniques recorded in scrolls and manuals revolve around ways to avoid detection, and methods of escape. These techniques were loosely grouped under corresponding natural elements. Some examples are:
Hitsuke – The practice of distracting guards by starting a fire away from the ninja's planned point of entry. Falls under "fire techniques" (katon-no-jutsu).
Tanuki-gakure – The practice of climbing a tree and camouflaging oneself within the foliage. Falls under "wood techniques" (mokuton-no-jutsu).
Ukigusa-gakure – The practice of throwing duckweed over water in order to conceal underwater movement. Falls under "water techniques" (suiton-no-jutsu).
Uzura-gakure – The practice of curling into a ball and remaining motionless in order to appear like a stone. Falls under "earth techniques" (doton-no-jutsu).
A komusō monk is one of many possible disguises.
The use of disguises is common and well documented. Disguises came in the form of priests, entertainers, fortune tellers, merchants, rōnin, and monks. The Buke Myōmokushō states,
Shinobi-monomi were people used in secret ways, and their duties were to go into the mountains and disguise themselves as firewood gatherers to discover and acquire the news about an enemy's territory... they were particularly expert at travelling in disguise.
A mountain ascetic (yamabushi) attire facilitated travel, as they were common and could travel freely between political boundaries. The loose robes of Buddhist priests also allowed concealed weapons, such as the tantō. Minstrel or sarugaku outfits could have allowed the ninja to spy in enemy buildings without rousing suspicion. Disguises as a komusō, a mendicant monk known for playing the shakuhachi, were also effective, as the large "basket" hats traditionally worn by them concealed the head completely.
Below is a video about Ninjutsu from The History Channel TV Series Human Weapon
Please refer to our references as we have used a few different sources for the basic explanation of each martial art discipline. Many of our direct links, images and text will be from the site Wikipedia which is not known for the most accurate information when it comes to doing a thesis or studying for ones P.H.D. but does have a large collection of data that is well organized. Much of the text regarding martial arts styles on Wikipedia seems to generally sum up each discipline as good as many other sources. We do not intend to re-invent the wheel, but we do want to roll you in a good direction in order to get a glimps of each style.