The Rasengan

The Rasengan (螺旋丸, literally "Spiraling Sphere", Viz "Spiral Chakra Sphere", Uzumaki Chronicles "Power Strike") is a technique invented by Minato Namikaze after three years of development. It requires no hand signs to perform, instead relying entirely on the chakra control of the user.[24] The Rasengan grinds into whatever it touches, causing major damage as well as significant internal injury. If need be, the potency of the attack can be lessened to keep from harming the target.

The level of chakra control required is very high, and because of this the teaching of this jutsu is split into steps in which the user learns to form their chakra into a spherical shape. Minato taught the Rasengan to his student, Kakashi Hatake, and his former teacher Jiraiya who in turn teaches it to Naruto Uzumaki. While most users of this jutsu are skilled enough to perform it with one hand, Naruto uses three or more hands with the aid of a shadow clone – one hand to supply chakra and the others to spin and shape it.[25] Though he continues to use this workaround to make the Rasengan simpler to form, Naruto has been able to create it single-handedly when covered in a Nine-Tailed Demon Fox shroud.

The Rasengan was created as the ultimate example of chakra form manipulation. However, Minato had intended to combine it with nature manipulation, which proved to be as impossible as "looking left and right at the same time". Minato and Kakashi have both been unsuccessful in the attempt.[26] In Part II, Naruto finally accomplishes the feat by using two shadow clones – one to manipulate form and one to infuse the Rasengan with his own wind-based chakra