Mangekuo

Tsunade returns to Konoha as the new Hokage. The villagers are eager to have her begin her official duties, but Naruto insists that she help Sasuke and Kakashi first. They run into Shikamaru along the way, who, given his history with women, is unhappy that the Hokage is a woman too. He later reluctantly has lunch with Team 10 to celebrate his appointment as a chūnin, the only advance in rank from the Chūnin Exams. Neji elsewhere tries to locate birds with his Byakugan, but can only see seven of eight. Tsunade heals Kakashi and Sasuke. Sakura is particularly happy with Sasuke's recovery, having stayed by his bedside since his encounter with Itachi. Guy pleads for Tsunade to look at Lee too.

Tsunade examines the damage to Lee's back and finds there are bone fragments lodged in his spine. Although she, and only she, could try removing them, Lee will die if she fails. Since her odds of success are only 50%, she advises he give up his dreams of being a ninja. To Guy's disappointment, Lee accepts his prognosis and leaves. While Team 10 is having lunch, Chōji insists that he get to have the last morsel of food, claiming it is the best. Asuma points out that he should train more and become a chūnin like Shikamaru, upsetting him. Sasuke, still recovering from his encounter with Itachi, thinks about how useless he was and how much Naruto has surpassed him. Orochimaru elsewhere sends his Sound Four to Konoha.

Naruto thinks about his lunch with Iruka. Iruka is happy with Naruto's development, but informs him that he will now need to start doing actual work. After the failed invasion of Konoha, the village is operating with a diminished manpower and ninja are being sent on more difficult missions and more often. Naruto is eager to start doing his part. After Team 10 has lunch, Ino tells Shikamaru that Chōji should go on a diet. Shikamaru defends him. Chōji tells Shikamaru that, now that he is a chūnin, his superiority to Sasuke and Neji is only more apparent. Shikamaru is unconcerned since he only wants to be himself, which he tells Chōji to strive for too. Naruto visits Sasuke in the hospital. Because so many others have shown a special interest in Naruto, Sasuke demands that they fight each other. Naruto accepts.

Over Sakura's objections, Naruto and Sasuke head to the hospital roof to fight. Regarding the battle casually, Naruto asks Sasuke to put on his Konoha headband. Sasuke refuses since that would mean that they are equals, upsetting Naruto for not acknowledging himself as Konoha ninja. Naruto surrounds Sasuke with shadow clones, which Sasuke destroys with his Fire Release: Great Fireball Technique. As the smoke clears Sasuke sees that one clone has survived and is helping Naruto form the Rasengan. He uses his own Chidori and they charge at each other. Sakura screams for them to stop.

Being the youngest son of Konoha Military Police Force captain and Uchiha clan head Fugaku Uchiha and his wife Mikoto and named after the father of the Third Hokage, Sasuke grew up in the shadow of his older brother, Itachi Uchiha. Itachi was an acknowledged prodigy who was viewed by the Uchiha clan as a genius, and whose work would further strengthen the bonds between the village and the clan. Sasuke's father in particular took an active interest in Itachi. Itachi, on the other hand, was rather ambivalent and full of oddly conflicting undercurrents, acknowledging Sasuke by taking interest in his progress as a ninja when even their father did not, but spending little quality time with Sasuke. Even after Sasuke enrolled in the Ninja Academy, he was still unable to escape Itachi's shadow. Despite consistently scoring at the top of every class, Sasuke failed to receive any recognition from his father, who defined Sasuke's success only in terms of his older brother. Itachi acknowledged the rivalry Sasuke felt, telling him, "We are brothers. I am the wall you must climb over, so you and I will continue to exist together."

Itachi's relationship with his father deteriorated further after Itachi was questioned by other members of the Uchiha clan regarding the apparent suicide of his best friend, Shisui. As Itachi's behavior became increasingly bizarre, Sasuke's father began spending more time with Sasuke, and began teaching him the Great Fireball Technique, a common family jutsu seen as a sign of coming of age in the Uchiha clan. When Sasuke first tried to perform the jutsu, he only had a small flame come out and after that, some smoke. His father said that Itachi was able to do it on his first try at Sasuke's age, which disappointed him. Later, with one week of training, Sasuke (age 7 at the time) performed the jutsu in front of his father, proving himself a genius as well in his own right and finally receiving his father's recognition. Sasuke's father told him that he could now proudly wear the clan's emblem on his back. Following this, Sasuke also received a stern warning not to follow in Itachi's footsteps any further, surprising him as before, he was told to be like him; and his father showing he was proud of Sasuke for the first time the same way as he used to with Itachi.
Sasuke activates his Sharingan for the first time.JacceAdded by Jacce
Shortly thereafter, Itachi massacred every member of the Uchiha clan, sparing only Sasuke, saying that he was not even worth killing. In addition, Itachi told him, "You've always wanted to surpass me. That's why I'm going to let you live... if you wish to kill me, then hate me, despise me... and by all means flee, cling to your wretched life." Itachi also revealed to Sasuke where the secret meeting place of the Uchiha was hidden, and suggested that Sasuke go there to learn what the true history and purpose of the Sharingan was. He told him that "to awaken the Mangekyō Sharingan," he "had to kill the person he was closest to", and that "when we battle, we should have the same eyes". Sasuke thought he had fainted after this, but later remembered that he had managed to stand back up, awaken his Sharingan, and pursue Itachi. Upon reaching Itachi, he managed to knock off his forehead protector. Itachi was seen shedding a tear as he was picking up the forehead protector. He then proceeded to incapacitate Sasuke, who awoke in the hospital remembering only that which Itachi wanted him to.

One day when they were younger, Sasuke accompanied Itachi on one of his training sessions. Impressed by Itachi's skills, Sasuke asked Itachi to teach him something, but Itachi, as always, refused by poking him on the forehead and promising to help him later. As they returned home, Sasuke marveled at the Uchiha clan's accomplishments as explained to him by Itachi. When they encountered their father, Fugaku, he spoke to Itachi about an approaching mission. Itachi refused to take part, wishing to take part in Sasuke's Academy orientation. Seeing that Itachi was determined, Fugaku volunteered to go in his place.