The Secrets of the Mangekyō Sharingan

As his recollection of boyhood reaches its end, Sasuke remembers coming back from the Ninja Academy to a home where every member of the Uchiha clan lay dead. Standing over his parents' bodies, he learned that Itachi had carried out the slaughter. His brother trapped him in the Mangekyo Sharingan and forced him to watch their parents die again, sending the terrified boy fleeing. Itachi halted him, coldly saying he was not even worth killing.

Before departing, Itachi told Sasuke that revenge for the clan would demand real strength, and he spelled out how the Uchiha's greatest power is obtained, that one must slay the person closest to them. Left alone to nurse his hatred, Sasuke swore he would do whatever it took to end his brother's life. In the present, his duel with Naruto resumes, and Sasuke names Naruto as that dearest friend, insisting he must kill him to gain the power needed to strike down Itachi.

In the manga, an unseen voice warns Sasuke not to enter before he finds Fugaku and Mikoto's corpses, a line absent from the anime, leaving the speaker unknown. Much of the footage is recycled from episode 84, with one telling change: the earlier version did not show Itachi's eyes shifting into the Mangekyo Sharingan during Tsukuyomi, because Masashi Kishimoto had not yet designed it, whereas this episode does depict the change. The installment adapts chapters 224 and 225.