"Driving Forces" (つき動かすもの, Tsukiugokasu Mono) is chapter 319 of the original Naruto manga.
As Asuma and his team depart for the Fire Temple, they take a detour passed Kurenai's apartment, who sees them go. Meanwhile, Naruto and his small group of shadow clones are unable to affect the waterfall they are training with. Naruto says he needs to use more shadow clones and thus a larger waterfall if he is to make any progress, but Kakashi advises against it. Naruto insists that he needs to catch up to Sasuke, so Kakashi instructs Yamato to make the waterfall bigger. Naruto trains through the night, motivated by Sasuke, and is eventually able to stop the waterfall with his wind release.