Jyuuken, which is used to refer to a gentle fist type taijutsu, is a name given to a style used in the anime Naruto. There are similar Martial Arts, though the overuse of the idea of the chakra in the cartoon is a bit extreme.
Hsing-i style and Pa qua style are the closest fighting styles to Jyuuken, and are interchangeable and often taught together. combined the two styles are about 90% the same as Jyuuken, right down to the use of eight trigrams, again, however, the idea of chakra in the anime is portrayed far more powerful than it actually is. Neji's fatal heart blow can not actually be performed with one strike, rather, five precise blows are necessary.
A good deal of Jyuuken, at least in Jyuuken Sentai Gekiranger, was based of of the beast system popular in kungfu, much in the same way that the four main styles of kungfu were the basis for Bending in Avatar: The Last Airbender. There is a Tiger Style (Jan, Dan) of kunfu, as well as a dragon style (Long). The others are blended versions of other styles, such as Gou's style, the primary base for it is Muay Thai, but are not outrightly those styles. The actual fighting style in Jyuuken Sentai Gekiranger is Kenpo, which is more or less translated as Beast Fist, further implies it's base in the beast system of kungfu.
sanji uses tokui taijutsu (leg taijutsu)
Considering that Taijutsu is an umbrella term, any style of Chinese martial arts could have it. However, since it is closely associated with Judo and Akido, Taijutsu could be applied to Taiji and Shuai Jiao wrestling.
taijutsu
It is taijutsu.
Budo Taijutsu
taijutsu
taijutsu
There is a mixed style of kung fu and taijutsu such as Baji Quan, Baji Quan, and Dim Mak.
it's obviously rock lee
if the boys parents are okay with it and the boy has a sound health then yes a thirteen year old boy can practice taijutsu.
ninjutsu, taijutsu and genjutsu
Masaaki Hatsumi is the grand master for taijutsu. He started the bujinkan dojo