Unforgivable! A Total Lack of Respect!

is episode 90 of the original Naruto anime.

Synopsis
While Tsunade was having dinner that night, Jiraiya and Naruto arrived at the same bar. Suspicious of Jiraiya's reason for searching for her, Tsunade asked what he wanted, to which he replied that Konoha wanted her to be the new Hokage. He even found out that Tsunade and Shizune had already found out about the Third's death and encountered Orochimaru along the way. She immediately rejected the offer, saying that anyone who would willingly take the title was a fool. Naruto, enraged that she would disrespect the title of Hokage and those who had held its position so bluntly, challenged Tsunade to a battle. The two stepped outside, and it was very clear that the Sannin is more powerful, as Tsunade sent Naruto flying by using only her index finger. Then she asked him what made him care about the Hokage so much. Naruto replies to her that his dream is to be Hokage someday. Tsunade then thought of her two most beloved Nawaki and Dan and their hopes of being Hokage as well. Naruto noticed she had lowered her guard, and unwilling to give up, he readied his imperfect Rasengan for an attack.