The main focus of "Tanaka-Ryu" Ninjitsu is, "To both gather and spread both health and wisdom". Ancient Ninjitsu had NO weapons ... old Ninjitsu had hundreds of classical weapons ranging from knives & swords, to spears & pole-arms, to bow & arrow, to whip & chain, to acids & bases, to poisons & explosives, and many more ... modern Ninjitsu favours no weapons, but includes and favours perfectly legal "non-weapons" as weapons ... such as the wooden cane, the umbrella, the kubotan, the newspaper or book, the fan, belts and sashes, a pen or pencil, the plastic credit card, hard toed shoes, fingernails with decoratively colored powdered stained glass in the nail polish, and so on ... but modern Ninjitsu still teaches brief introductions to all of the old classical weapons, but because these weapons are not legal to openly carry anywhere and everywhere, the modern Ninja only trains heavily with legal "non-weapons" ... my style highly recommends the wooden cane ... The first Ninja BECAME a farmer ... at a time when there were only hunters and gatherers, BEFORE there was such a thing as farming in Japan, it was the first Ninja who learned how to plant and raise and harvest desirable herbal medicines and fruit trees so that these things would no longer have to be searched for. Although there is a subtle difference between Jitsu and Jutsu ... the spelling difference is mainly a result of various European nations trying to put the sound of the Japanese word into an alphabetically lettered word ... the French, English, German, Italian, Dutch, Spanish, and Portuguese did not all agree on how to spell the sound.

The difference in spelling between jitsu and jutsu is down to a revision in the Hepburn system for the romanisation of Japanese words. 'u' sounds in Japanese are often contracted or omitted, such as in onegaishimasu - pronounced "on-eh-gai-shi-mass", and for a martial arts example, tsuki is pronounced "ts'ki". "jitsu" was the original representation of what was heard when people say "j'ts", but it lead to people not being able to recreate the sound, and so was revised to "jutsu" as a closer approximation. As for the first ninja, it really depends whose history you want to believe. Ninjutsu is extremely unlikely to have had a single originator, or even a single starting location; more honourable martial arts schools often had a section dealing with the the more underhanded means, which today we would call ninjutsu. Skills developed from the non-warrior classes would also be called this way. The word today is a broad term for a variety of means, all of which produced similar end results. This also means that the focus of Ninjutsu, the tools and weapons used, really depends on when in history you're talking about, and the people involved.

The term Shinobi, is the old term for the more modern one of nijitsu, the Iga ryu, and Koga ryu are the primary schools of nijitsu, the Koga ryu was made up of 47 different martial arts ryu, the Iga ryu 39. they were noted for their vast network of agents for information gathering, they were often refered to as Kusa, or Rappa, some ryu were developed for special reasons like the Fuma ryu who specialty was fire arms and explosives. They were farmers and fishermen liveing in the remote areas of Japan, most of there weapons were nothing more than tools used in every day life. Common tools could be taken with them while traveling without being stoped by samurai, Fishing nets, kamas, staff, or walking sticks were most common. some held hidden weapons like weighted chain, shaken, and shuriken. Not all Shinobi were farmers, many were Ronin, masterless samurai or regular samurai like Hattori Honzo who was a general and also the Jonin, or head of one of the Iga ryu ninjitsu familys.

Main focus of Ninjitsu is to be a well rounded person who is not defenseless. In US any class seems to focus on killing, though. Ninjitsu is a very effective method of killing and has become known for that. As with anything else in the US, it is sold for what it is known best.