A New Chapter Begins: The Chūnin Exam!

is episode 20 of the original Naruto anime.

Synopsis
After completing their mission in the Land of Waves, Team 7 finally returns to Konohagakure. Although Sasuke saved Naruto's life their teamwork seems to have gotten even worse than before. When Team 7 resume missions, Naruto Uzumaki is only focused on beating Sasuke, causing him to screw up in all of the missions. He weeds a woman's garden but also pulls out her special herbs. He nearly falls off a waterfall before being saved by Sasuke yet again. He then chooses the largest dog to walk, which he can not control and is dragged off into a mine field. Kakashi decides that their teamwork is too off that day and sends them all home. Before they return home Sasuke aggravates Naruto even more by claiming that Naruto wants to get better to just become stronger than him. Before Sasuke leaves, Sakura asks him if they can work on their "teamwork". Sasuke says that if she has time to flirt she should be working on her skills. He then crushes her by claiming she's as bad as Naruto, then delivers the final blow by saying that she is even worse than Naruto.

A small box stalks Naruto, and explodes, revealing Konohamaru and his two friends: Udon and Moegi. They reveal themselves as the Konohamaru ninja squad. Konohamaru wonders about Naruto and Sakura's relationship. He then comes to the conclusion that they are dating, which Naruto says is true. Sakura, already angry by Sasuke's comment, punches Naruto in the face and sends him into a fence. Konohamaru then insults Sakura and she chases after all four of them. Konohamaru eventually bumps into an evil-looking ninja from another village. He picks Konohamaru up and threatens to kill him.

Naruto attempts to attack the newcomer but is suddenly tripped by his invisible attack. Just as the mysterious ninja is about to hit Konohamaru, Sasuke saves the day by forcing the ninja to drop Konohamaru. Just as the mysterious ninja is about to attack Sasuke, another, even more evil looking ninja appears. He reveals himself as Gaara of the Desert, and we also find out that the other evil looking ninja is named Kankurō, and the girl ninja is named Temari. Everyone is impressed by Sasuke's rescue, Konohamaru upsets Naruto by saying that, compared to Sasuke, Naruto is pretty lame. The three ninja from the other village reveal they they are from the village hidden in the sand, from the Land of Wind. They add that they are in Konoha to attend the Chūnin Exams: the exams that decide whether or not you upgrade from a Genin.

Meanwhile, all the higher level ninja are gathered along with the Hokage. The Hokage announces that the chūnin exams will take place in seven days on July 1st.

Trivia

 * Interestingly, the key Naruto uses to lock his door is Pakkun, Kakashi's ninken.