Itachi Shinden Book: Light and Darkness

This Naruto: Shippuden storyline spans episodes 451 to the opening of 458 and serves as a pause before the Kaguya Otsutsuki Strikes storyline begins. It draws its title from two of the Naruto Shinden novels, the Book of Bright Light and the Book of Dark Night, though beyond the name it shares little with them. The focus rests entirely on Itachi Uchiha's path leading up to and beyond the fall of his clan.

At four years old Itachi already witnesses the horrors of the Third Shinobi World War, killing a wounded enemy in self-defence and pressing his father to explain what war truly means. A meeting with Orochimaru plants doubts about how one should live, and the birth of his brother Sasuke gives him a bond he comes to treasure. When the Nine-Tails ravages Konoha he shields Sasuke and rescues Izumi, and afterward Danzo relocates the Uchiha to the village's edge under a cloud of suspicion.

Itachi excels at the Academy, befriends Shisui over shared hopes of ending violence, and graduates at seven. The death of his teammate Tenma at a masked man's hands awakens his Sharingan, and his rise into the Anbu draws him into spying for both clan and village as tensions boil toward a coup. Shisui's suicide, entrusting his eye to Itachi, triggers the Mangekyo Sharingan. Caught between the elders and his family, Itachi is given a merciless choice by Danzo: perish alongside a rebelling clan or slaughter it and spare Sasuke alone. He accepts the masked man's aid and carries out the massacre, killing even his accepting parents before reporting to Hiruzen and departing to join the Akatsuki.

Within Akatsuki, Itachi is first paired with Juzo Biwa, whom he is forced to kill during a mission to the Land of Water after Yagura's assault, then permanently partnered with Kisame Hoshigaki. He takes part in the organisation's assassinations and recruitments, from Deidara to Hidan, all the while quietly watching over Sasuke's safety from afar. On a return to Konoha he brutally overpowers his brother and burns cruelty into him with Tsukuyomi to sharpen his hatred.

Years on, a conversation with Naruto, who vows to save Sasuke without killing him, convinces Itachi to place his trust in the boy. In their final duel Itachi succumbs to his illness and gives Sasuke one last tap on the forehead. Later reanimated and helping stop Kabuto at Sasuke's side, he tells his brother he needs no forgiveness and will love him no matter which path he walks, before his soul returns at last to the afterlife.