Yu

Biodata

Feature	Information
Name	Yu Uchiha (鱼又)
Alias(es)	Yuyou; Yuyouyou Uchiha; Blue Giant
Species/Race	Human; Uchiha clan member
Gender	Male
Affiliation	Konohagakure; Uchiha clan; Slime Clan; Allied Shinobi Forces
Occupation/Role	Uchiha clan head; Hokage; ninja; Slime researcher and creator
Status	Alive
First Appearance	Chapter 1

Power Progression

Stage / Realm / Level	Chapter	Notes
Beast God Crystal / Slime bloodline	1	Possesses the Beast God Crystal, which can obtain bloodlines; gains the Slime bloodline after his initial death.
Slime survival traits	3	Discovers physical-damage nullification and powerful vitality; survives by feigning death.
Great Fireball Technique	17	Learns his first offensive ninjutsu, prioritizing mastery of the Uchiha Fire Release technique.
Chakra Heart	17 47	Develops Chakra Hearts to overcome his original low chakra reserves; later dedicates one to maintain his Sharingan continuously.
Somersault Cloud Slime	36 37	Creates and summons a flying Slime with Pufferfish, Archerfish, and Kapok Tree bloodlines.
One-Tomoe Sharingan, permanently active	47	Activates the Sharingan continuously; more than doubles his ninjutsu-learning talent and enables rapid progress with Shadow Clones.
Chakra Metal Skeleton	51	Upgrades his chakra-metal body framework and uses it to intimidate Tazuna.
Shadow Clone Technique	63	Masters the technique and creates five clones to train, research, and learn in parallel.
Advanced elemental ninjutsu	72	Defends against coordinated B-rank attacks with an Earth Style Wall, then uses Great Fire Dragon Technique.
Blue Giant form	102 103	Publicly reveals himself as Konoha’s Blue Giant during his inauguration; uses Lion Heart Technique to calm a crowd.
Shisui’s Mangekyō Sharingan / Kotoamatsukami	115	Transplants Shisui’s Mangekyō Sharingan onto his forehead and connects it to a Chakra Heart; Kotoamatsukami is initially on cooldown.
Samehada	121	Subdues and claims Kisame’s chakra-devouring sword through superior chakra reserves and a blue longsword.
Enhanced genjutsu mastery	129 130 131	Resists Yakumo Kurama’s genjutsu, enters her mindscape, suppresses Demon Ido with his Three-Tomoe Sharingan, and guides Yakumo’s recovery.
Tailed Beast combat method	147	Battles Shukaku without using the Sharingan; learns that relentless attacks can prevent a Tailed Beast from charging major techniques.
Six Paths-equivalent power	247	Assesses his own strength as equivalent to the Six Paths level, while continuing preparations against the Ōtsutsuki Clan.

Background / History

Yu is a reborn Uchiha who retains knowledge of the Naruto world and possesses the Beast God Crystal. During the Uchiha clan massacre, he attempts to flee but is fatally injured. His Slime bloodline subsequently gives him the durability and vitality to survive by pretending to be dead. 1 3

Sasuke carries Yu through the compound during the massacre. Yu attempts to restrain Itachi so Sasuke can escape, then later receives protection from Sasuke and Hiruzen Sarutobi when Danzō seeks to keep him. 3 4 Afterward, Yu decides to remain in Konoha, where he and Sasuke live in the Uchiha compound and formally establish their bond as brothers. 7

His earliest years are limited by extremely low chakra reserves and poor skill with thrown weapons. Although his Slime bloodline grants exceptional survivability, it initially has low growth potential and makes chakra refinement difficult. 8 Yu responds through experimentation, Chakra Hearts, Slime cultivation, and eventually the Sharingan, transforming from a weak survivor into an overwhelmingly powerful shinobi. 17 47

Following his role in defending Konoha during the Konoha Crush, Yu seeks to restore the Uchiha clan. Sasuke recognizes him as clan head, and Yu is formally inaugurated at the ancestral hall. 100 101 He reclaims the clan head’s right to attend Konoha’s high-level meetings and begins rebuilding the clan’s political standing, membership, industry, and influence. 104 125 202

Yu later becomes Hokage and takes a proactive role in preparing Konoha and the wider ninja world against the Akatsuki Organization and the Ōtsutsuki Clan. 173 182 247

Personality

Yu is pragmatic, strategic, and intensely focused on survival, power, and long-term preparation. Early on, he avoids drastic changes to known events and keeps a low profile because he fears the consequences of attracting attention. 18

He is ambitious but not purely destructive. His aims expand from gaining strength and control over Konoha to rebuilding the Uchiha clan, protecting its members, and ultimately creating a new civilization rather than merely ruling the world. 63 184 He values useful talent regardless of background, recruiting engineers, researchers, civilian ninjas, and orphans to strengthen the Uchiha clan. 125 136 202

Yu can be manipulative and ruthless toward enemies, as demonstrated by his deception of Danzō, seizure of Root’s assets, and plans to control Orochimaru. 113 116 However, he also shows mercy and practical restraint, sparing Zabuza before later making him a subordinate, helping Yakumo confront her trauma, and allowing Itachi to live because of his potential value to Sasuke. 56 131 235

Abilities & Skills

Slime Bloodline and Slime Creation

Yu’s Slime bloodline grants extreme survivability and forms the basis of his research, combat force, and infrastructure.

• Nullifies or resists physical damage and possesses extraordinary vitality. 3
• Originally suffers from low chakra reserves and limited growth potential despite his durable body. 8
• Produces specialized Slimes for transportation, reconnaissance, laboratory work, combat, and infiltration. 18 36 70 166
• Uses Shape-shifting Slimes as disguised Sharingan to deceive Danzō and avoid Kotoamatsukami’s control. 113
• Maintains an underground Slime World developed with Orochimaru’s assistance. 247

Chakra Hearts

Yu develops multiple Chakra Hearts to solve his chakra shortage and fuel high-consumption abilities.

• Supplies chakra for permanently active Sharingan. 47
• Supports immense chakra reserves that others compare to Kage-level or Tailed Beast-level power. 51 210
• Activates all sixteen Chakra Hearts during his confrontation with Obito. 210

Sharingan and Genjutsu

Yu possesses the Uchiha Sharingan, later supplementing it with Shisui’s Mangekyō Sharingan.

• Keeps his Sharingan active continuously without the chakra burden suffered by most users. 47
• Greatly improves ninjutsu learning and helps him master the Shadow Clone Technique. 47 63
• Sees through Zabuza’s Hidden Mist and counters Silent Killing. 54
• Possesses genjutsu resistance described as second only to Itachi’s. 129
• Enters mental spaces, dispels genjutsu, and suppresses Demon Ido using his Three-Tomoe Sharingan. 130
• Gains access to Kotoamatsukami after transplanting Shisui’s Mangekyō Sharingan. 115

Ninjutsu

Yu employs multiple chakra natures and combines high-output techniques with tactical adaptability.

• Fire Release — Uses Great Fireball Technique, Hosenka no Jutsu, and Great Fire Dragon Technique. 17 39 51 72
• Water Release — Uses Waterfall Technique to extinguish the blaze caused by his Great Fireball. 39
• Earth Release — Uses Earth Style Wall against several simultaneous B-rank attacks and Earth Splitting Core to breach Orochimaru’s barrier. 72 166
• Wind Release — Blasts Kisame back while claiming Samehada. 121
• Lightning Release — Uses Lightning Cannon during the assault on Orochimaru’s stronghold. 166
• Body Flicker Technique — Learns the technique but considers its direct combat value limited. 18
• Shadow Clone Technique — Uses clones to delegate research, train, gather intelligence, and conduct operations. 63 70 116
• Eight Directions Sealing Prison — Uses clones and the sealing technique to trap Obito’s Kamui dimension. 210

Taijutsu and Giant Form

Yu is capable of direct close-quarters combat against elite opponents.

• Defeats Meizu with a single punch and kills Gozu with a chakra-metal sword. 50
• Breaks Zabuza’s Kubikiribōchō and exchanges taijutsu with him. 54
• Assumes a blue armored giant form and physically overwhelms Shukaku while denying it time to form a Tailed Beast Bomb. 147
• Uses Lion Heart Technique to pacify a panicked crowd during his inauguration. 103

Research and Leadership

Yu applies experimentation, knowledge from his previous life, and delegation to expand his power and influence.

• Studies the regenerative formation core of Kubikiribōchō. 61
• Seizes Root’s research data, equipment, materials, and the Izanagi method. 116
• Recruits Orochimaru and Kabuto into his research organization. 174
• Supports industrial development, including the Konoha No. 1 car prototype and a planned construction company. 125 134

Equipment / Weapons / Items

• Beast God Crystal — A “golden finger” that enables Yu to obtain bloodlines. 1
• Kubikiribōchō — Zabuza’s executioner blade; Yu researches its regenerative metal-strip formation. 59 61
• Samehada — Kisame’s chakra-absorbing sword, subdued and claimed by Yu. 121
• Blue longsword — Used to force Samehada into submission. 121
• Chakra Metal Skeleton — An upgraded chakra-metal framework used in combat and intimidation. 51
• Shisui’s Mangekyō Sharingan — Implanted on Yu’s forehead to obtain Kotoamatsukami. 115
• Black feather — A contact method given by Hiruzen to summon Itachi. 204

Relationships

• Uchiha Sasuke — Adoptive brother-like companion and the person Yu trusts most; Sasuke supports Yu’s claim as Uchiha clan head. 3 7 101
• Uchiha Itachi — Yu blames Itachi for the massacre and later confronts him over it, though he permits Itachi to live for Sasuke’s development. 205 235
• Sarutobi Hiruzen — Hiruzen saves Yu from Danzō after the massacre; Yu later works with him as a political ally and seeks his support against Akatsuki. 4 106 182
• Shimura Danzō — Hostile political opponent who sought to control Yu with Kotoamatsukami; Yu deceives and defeats him. 60 113
• Fujiwara Chima — Teammate and trainee whom Yu personally trains in defense. 45 82
• Sai — Team 99 teammate assigned by Danzō to befriend Yu and integrate into the team. 45
• Yamashiro Aoba — Former instructor who tests Yu during his Genin examination and recognizes his exceptional potential. 37 39
• Zabuza Momochi — Defeated opponent whom Yu initially spares and offers employment; Zabuza is later killed. 56 60
• Orochimaru — Former adversary and prospective vessel seeker whom Yu later recruits for Slime Clan research. 70 174
• Yakumo Kurama — Yu frees her from Demon Ido’s influence and gains the Kurama clan’s friendship. 130 131 132
• Yunshang Jinwei — Uchiha steward and later clan member; manages the compound and organizes Yu’s inauguration. 101
• Chizoe Juji — Engineer recruited by Yu to develop Konoha No. 1 and support the Uchiha clan’s rebuilding. 125

Story Role / Major Arcs

Uchiha Clan Massacre

Yu is caught in the massacre shortly after his rebirth. After being mortally injured, he survives through the Slime bloodline, protects Sasuke’s escape, and is taken away by Hiruzen. 1 3 4

Early Development and Team 99

Yu remains in Konoha, studies ninjutsu, develops Chakra Hearts and Slimes, and joins Team 99 with Sai and Fujiwara Chima under Yamashiro Aoba. 18 36 37 He reveals exceptional elemental ninjutsu during Aoba’s bell test and later demonstrates his combat superiority on the Land of Waves mission. 39 50

Land of Waves and Zabuza Conflict

Yu defeats the Demon Brothers, pursues Zabuza alone, breaks Kubikiribōchō, and forces Zabuza into submission. 50 53 54 56 His return with Zabuza and the blade draws concern from Konoha’s leadership regarding his power and Uchiha heritage. 59 60

Uchiha Restoration

After gaining public recognition for saving Konoha, Yu assumes the Uchiha clan head position with Sasuke’s support. 100 101 He reveals himself as the Blue Giant, reclaims the clan’s political rights, recruits new members and specialists, and seeks the Fifth Hokage position. 102 104 124 125

Danzō and Root

Danzō attempts to enslave Yu with Kotoamatsukami. Yu instead reveals that his apparent Sharingan were Slimes, removes Danzō’s arm and Sharingan, and takes Root’s research legacy. 113 116

Kurama Clan Incident

Yu allies with the Kurama clan by treating Yakumo. He withstands her genjutsu, suppresses Demon Ido, guides her through repressed memories, and helps her extract the entity. 126 129 130 131

Tailed Beast and Akatsuki Preparation

Yu fights Shukaku to test his strength, later recruits Orochimaru and Kabuto, and prepares Konoha for Akatsuki. 147 174 182 He infiltrates Amegakure, confronts Itachi over the massacre, and uses the Eight Directions Sealing Prison against Obito. 184 205 210

Hokage and Future Threats

As Hokage, Yu focuses on the reconstruction and protection of Konoha, while preparing the ninja world for the Ōtsutsuki Clan. 173 182 247

Trivia

• Yu’s original chakra reserves were so low that he struggled to use even the Three Body Technique. 8
• He initially missed targets with kunai and shuriken nine times out of ten despite his Uchiha heritage. 8
• Yu’s permanent Sharingan activation becomes a conspicuous sight on Konoha’s streets. 47
• He has an undergraduate degree from his previous life and applies that knowledge to political and industrial planning. 123
• Yu establishes the rule that the Uchiha clan will protect every member and provides rescued orphans with resources and education. 202