Wind Release: Rasengan

The Wind Release: Rasengan is an original technique created by Naruto Uzumaki.

Overview
Minato Namikaze created the Rasengan with the intention of combining it with his own nature, a task that proved too difficult for him to complete prior to his death. Kakashi Hatake also failed to combine the Rasengan with his own lightning-nature, causing him to invent the Chidori instead. Naruto initially struggles to combine the Rasengan with his wind-nature despite using shadow clones, which he describes as needing to look left and right at the same time. He is eventually able to overcome this obstacle by using shadow clones: he provides the chakra, one shadow clone shapes the chakra into a sphere, and a second infuses the sphere with wind. The end product becomes the Wind Release: Rasengan. Users who have mastered the Rasengan's shape transformation will only need one shadow clone, to provide the wind-nature, and with additional experience users can perform it without any shadow clones at all.

Naruto's Wind Release: Rasengan appears largely identical to the standard Rasengan, though it's shown to be stronger. When used in combination with other jutsu, as in the case of the Typhoon Water Vortex Technique, its wind nature can expand the other jutsu's coverage area. Naruto invents the Wind Release: Rasenshuriken shortly after he figures out the principles of the Wind Release: Rasengan, and for that reason he rarely uses the Wind Release: Rasengan.

Tailed Beast Influence
In the Sasuke Shinden novel, Naruto uses the power of the Nine-Tails to form a Wind Release: Rasengan that he's able to throw; he also doesn't need any shadow clones to create it. When it hits its target, it creates a shockwave of wind away from Naruto. In the anime, Naruto instead uses "Rasengan: Flash".

Trivia

 * In the anime, Asura Ōtsutsuki developed Amenomihashira, a precursor to this technique.