I Woke Up in Naruto With My Brother's Knife in My Chest, So I Absorbed Him and Took His Eyes

Summary

A 28-year-old doctor wakes up as Nan, a six-year-old Uchiha, with his older brother’s knife buried in his chest. His brother explains that he stabbed Nan to awaken the Mangekyo Sharingan: he believes strength is the only way to defy fate after losing their parents to war.

But Nan’s own eyes awaken too. Their forbidden power, Formless Reincarnation, absorbs his brother—memories, abilities, and all—and leaves Nan with his brother’s eyes as well. The fusion gives him an Eternal Mangekyo, a chakra-powered set of phantom bodies, and a dangerous ability to take on the faces of those he absorbs. His first accidental clone is a tree, a particularly unhelpful start to his new career.

Nan soon realizes he hasn’t stolen a child’s body: he and the original boy are the same soul, and memories of his past life have resurfaced. He hides his overwhelming abilities behind the image of a gifted but ordinary kid while training at an absurd pace. He convinces his teacher to let a shadow clone attend class, spars with young Shisui, and teams up with Kakashi to develop lightning techniques. Kakashi estimates that mastering lightning will take six months; Nan dryly corrects him: with clone training, he does it in three weeks. He also tricks Might Guy into believing that relentless blinking will improve the Sharingan, briefly creating Konoha’s two “blinking maniacs.”

For taijutsu, Nan tracks down the supposedly dead master Chen by accusing him of stealing his own grave offerings. Guy’s attack forces Chen to reveal the Konoha Dragon God technique, which Nan copies with his Sharingan. Guy eventually earns Chen’s respect and learns the technique himself. Nan then combines lightning chakra with medical knowledge of nerves and reflexes to create Speed Force—his comic-book-inspired name for a technique that lets his small body move as fast as his mind.

After graduating at six, Nan joins Orochimaru’s team alongside Anko and Hayate. Orochimaru hopes to turn the orphaned prodigy into a trusted medical assistant for his experiments, while Nan politely pretends to be an adoring student and quietly considers his escape routes. On the front, Nan diagnoses and treats a deadly hidden infection in the Sand’s poison, using a difficult medical technique and shadow clones to keep more soldiers alive. His success earns him a mission to find Tsunade, who helps develop the antidote.

Nan gets Tsunade’s attention by challenging her to a fight over her insult to the Hokage. He loses, of course, but points out that she broke her own one-finger rule. Shizune backs him up, forcing Tsunade to apologize. The encounter also gives Nan a mentor who understands both medicine and combat. He learns her chakra-storage seal and strength techniques, and is touched when she recognizes him as her late mother’s son. He also heals Hayate’s persistent cough, quietly improving the fate of a future character.

On his journey home, Sand ninja ambush Nan. He defeats them with a mix of clones, medical tricks, lightning, and Tsunade’s strength, then lets one young sensor survive so the Sand will hear a carefully edited version of how strong he is. The Hokage responds by giving him a few days off—an underwhelming reward Nan grumbles about—while Danzo tries and fails to recruit him into Root. Nan escapes Danzo’s basement with Flying Thunder God, then visits Fugaku, who gives him valuable Uchiha genjutsu notes. When Nan hints that his brother spoke of “future eyes,” Fugaku assumes the worst and becomes protective of him.

Nan also secretly places part of himself in Kabuto, creating a second body with its own mind and perspective. It lets him think and train in two places at once, though the new body is badly nearsighted; Nan jokes about creating the clan’s first “nearsighted Sharingan user.” He gives Kabuto a home with the orphanage caretaker Nonō and hopes to spare him the tragic future he knows from the original story. The plan leads to a confrontation with Sasori, who had planted Kabuto as a sleeper agent. Nan defeats Sasori, absorbs his skills and knowledge, and turns the Third Kazekage puppet into a powerful weapon.

The war escalates when Nan’s village is threatened by the Cloud. He builds an army of self-operating puppets powered by chakra-rich stones and a tree linked to his own chakra. Rather than expose his identity, he appears as Sedo, the Sound Shadow, and offers the Land of Rice Fields protection in exchange for backing a new ninja village.

Nan then faces the Raikage in front of both armies. He can’t match the Raikage’s speed and strength directly, so he uses sound-based techniques and a precisely timed vibration to redirect the Raikage’s supposedly unstoppable spear into his own chest. The Raikage survives, but the Cloud force is routed. Nan keeps his promise not to kill him, and the Land of Rice Fields announces the founding of the Hidden Sound Village.

Notable Jokes and Reactions

Nan’s narration repeatedly punctures the grand anime drama with dry observations:

• His first eye technique turns a tree into a clone.
• Kakashi’s training estimate ignores clone mathematics.
• Guy takes the fake blinking lesson completely seriously.
• Nan complains that the Hokage’s reward for saving lives is “a few days off.”

His funniest gambits usually rely on playing innocent—whether he is pretending to be a grieving child, flattering Orochimaru, or acting like a harmless little boy in Danzo’s basement.

Personalities Appearing

Nan; his older brother; Madara and Zetsu; Shisui; Kakashi; Might Guy; Chen; Hiruzen (the Third Hokage); Orochimaru; Anko; Hayate; Nonō; Kabuto; Danzo; Fugaku; Minato; Kushina; Shizune; Tsunade; Jiraiya; Pakura; Rasa; Chiyo; Ebizo; Shukaku and its host; Sasori; the Third Raikage; and Kamura, the samurai survivor.