Chakra level of control that is required is very high because the teaching of this technique is made in three stages. The first phase of the Phase Rotation, trained with the play in the water until the water balloon is broken. Phase two, the Phase Power, trained by solving a rubber ball. The third stage is Phase Control, trained by combining the first and second phase so that a perfect round shape and compact. Jiraiya teaches Rasengan in the fourth Hokage and then taught to Naruto Uzumaki.
Almost all users of this technique using one hand to use it, but Naruto wear one or two kagebunshin / shadow to do so. Kagebunshin make use of a high-level techniques to control this in a little time.
Rasengan is an example of manipulation Chakra high level. In addition, the Fourth Hokage died before TO COMPLETE with its own type of chakranya while Kakashi failed to refine this moment with his own manipulation chakran. In the PS2 game console, "Naruto Narutimate Accel", Jiraiya can refine Rasengan Chakra with the type of fire. In Naruto Shippudeen Naruto become successful completed Rasen Shuriken that with his wind element.
