The Will of Fire Still Burns!

is episode 99 of the original Naruto anime.

Synopsis
Konohamaru, the Third Hokage's grandson, was at first unaccepting of Tsunade as his grandfather's successor, and did what he could to prevent her inauguration. As Tsunade did some research in hopes of increasing the chances of Lee's surviving the operation, Naruto tried to convince Konohamaru that she would be a good Hokage. After Tsunade demonstrated her strength and healing abilities, Konohamaru decided that Tsunade could be Hokage, and that his grandfather wouldn't fade into memory. Meanwhile, Lee is still sulking from what Tsunade tells him about the operation and Sakura tries to cheer him up.