Blue B

Biodata

Feature	Details
Name	Blue B
Alias(es)	Aosui
Gender	Male
Affiliation	Konoha; Scientific Research Department
Occupation/Role	Danzo's disciple; core researcher of the Scientific Research Department
Status	Alive; Momoshiki's Jinchūriki
First Appearance	Chapter 272

Power Progression

Stage / Realm / Level	Chapter	Notes
Momoshiki's Jinchūriki	272	Deliberately allows the injured Momoshiki to implant Karma in his body, then traps and seals him within his Mental Space using Sage Dōjutsu: Yomi Possession. This gives him a living Ōtsutsuki research subject and a potential route beyond his talent ceiling.

Background / History

Blue B is Danzo's beloved disciple. Despite having grown into a young man, Danzo still regards him as a child and is visibly alarmed when he charges toward Momoshiki rather than retreating. Among the people Danzo cares most deeply about, Blue B is named alongside Hiruzen Sarutobi and Senju Tobirama. 272

At some point years earlier, Hiruzen Sarutobi rode the Five-Tails, wielded the Enma War Halberd, and rescued Danzo and Aosui from the formations of ten thousand Iwagakure and Kumogakure troops. This rescue became one of the memories tied to Danzo's long-standing resolve to stand properly beside Hiruzen as an aide worthy of the Third Hokage. 274

He is regarded as the future of the Uchiha Clan and its undisputed next Clan Head. Fugaku and Isshin fear the consequences for the clan should he be harmed, particularly because Sasuke is still young. 272

Orochimaru identifies Blue B as the acknowledged core of Konoha's Scientific Research Department. He attributes Blue B's readiness to confront Momoshiki directly to a researcher's desire for firsthand data and calls him a “pureblood ‘Tobirama-style’ researcher.” 272

Personality

Blue B is intensely rational, ambitious, and research-driven. Rather than merely defend against Ōtsutsuki parasitism, he intentionally becomes Momoshiki's host so Konoha can study an active Ōtsutsuki specimen. 272

He frames the risk as necessary for Konoha's research, though Izuna accuses him of also wanting to monopolize Ōtsutsuki research before anyone else can claim it. Blue B reacts defensively to the implication that his position depends on Hiruzen's protection rather than his own intellect. 272

His treatment of Momoshiki is coldly methodical: he plans to leave the captive sealed and uncomfortable until the Ōtsutsuki's arrogance is worn down enough for negotiation. 272

Abilities & Skills

Sage Dōjutsu: Yomi Possession

Blue B opens rifts from his Mental Space to his personal alternate dimension, Yomi, and uses its toxic waters to restrain and poison Momoshiki. 272

• Floods Momoshiki's body with toxins enhanced by Chakra and dense Natural Energy. 272
• Uses Yomi's waters and a giant hand from the dimension to immobilize and seal Momoshiki. 272
• Can adjust the technique's intensity after sealing to maintain pressure on the captive. 272
• Its techniques resist Momoshiki's Takamimusubinokami-based Deconstruction. 272

Mental Space and Spiritual Resilience

Blue B's Mental Space is difficult for Karma to infiltrate or alter, turning Momoshiki's attempted possession into a trap. 272

• His soul was strengthened ten years earlier through Sukunahikona Healing using Isshin's Mangekyō Sharingan dōjutsu power. 272
• Long-term assimilation with Izuna further reinforced his spirit. 272
• He continually tempers his soul and spirit with advanced Forbidden Techniques. 272
• Momoshiki can imprint Karma only faintly due to Blue B's unusually sturdy soul. 272

Rinnegan and Limbo Clones

Blue B synchronizes his Rinnegan with Izuna's and deploys Limbo Clones during the sealing operation. 272

• The synchronized Rinnegan emit purple light while the pair restrain Momoshiki. 272
• Limbo Clones pin Momoshiki's limbs and are unaffected by Yomi's waters. 272

Technique Structure Resistance

Blue B's techniques are difficult for Momoshiki to absorb or Deconstruct. This is attributed to the Shinobi World's training against Hiruzen's Spirit Release, which taught shinobi to maintain stable technique structures. 272

Equipment / Items

• Long blade — wielded when Momoshiki approaches; Blue B cuts down Momoshiki's physical body as the Ōtsutsuki transfers his material information through Karma. 272

Relationships

• Danzo — Teacher and deeply protective mentor; Danzo considers Blue B one of the three people he cares for most. Danzo and Aosui were once rescued together by Hiruzen from ten thousand Iwagakure and Kumogakure troops. Danzo is later completely annihilated while using his ultimate Forbidden Technique against Zoshiki. 272 274
• Hiruzen Sarutobi — A powerful protector whose concern for Blue B is noted by Izuna; Blue B has discussed Forbidden Jutsu research with him in the Amenominaka space. Hiruzen also once rescued Danzo and Aosui while riding the Five-Tails and wielding the Enma War Halberd. 272 274
• Izuna — Close collaborator connected through the Yata Imperial Spirit; lends Blue B Chakra and helps seal Momoshiki. 272
• Orochimaru — Fellow researcher who recognizes Blue B as the Scientific Research Department's core and understands his motivations. 272
• Momoshiki Ōtsutsuki — Captive sealed within Blue B's body as a Jinchūriki and research subject. 272
• Fugaku and Isshin — Allies concerned for his safety and position as future Uchiha Clan Head. 272
• Uzumaki Shio and Tomie — Rivals who want to settle past resentment with him in a fair promotion battle. 272

Story Role / Major Arcs

Momoshiki's Capture

Blue B charges toward the heavily injured Momoshiki despite warnings from Danzo and other shinobi. He knowingly permits Momoshiki to implant Karma, intending to make himself the Ōtsutsuki's Jinchūriki rather than fall victim to an uncontrolled possession. 272

Inside his Mental Space, Blue B reveals that the apparent possession is an ambush. With Izuna's Chakra and assistance, he uses Yomi Possession, Limbo Clones, and the Yomi dimension's restraints to poison and permanently seal Momoshiki within himself. 272

Blue B explains that Konoha needs an active Ōtsutsuki “standard sample” for research and regards Momoshiki as the prototype unit for future data collection. He also sees the arrangement as a path toward surpassing his own talent ceiling. 272

Danzo's Final Battle Against Zoshiki

During Danzo's ultimate confrontation with Zoshiki, the narration recalls a formative earlier event in which Hiruzen rescued Danzo and Aosui from the formations of ten thousand Iwagakure and Kumogakure troops. Danzo's memories of that rescue are linked to his lifelong effort to become a worthy aide to Hiruzen. 274

Danzo later sacrifices himself by activating Sage Art: Giant Tornado Storm, combining Spirit Release, Natural Energy from the Three Great Sage Regions, Mutual Explosion Tags, and the Mutually Multiplying Reverse Four-Symbols Sealing Technique to devastate Zoshiki. The explosion annihilates Danzo's flesh, spirit, and soul so completely that even ordinary resurrection would be impossible without power capable of reversing entropy. 274

Notable Quotes

“Konoha needs to analyze the abilities of the so-called Otsutsuki clan. The best way is to have a standard sample.” 272

“From now on, we'll be spending some time together. I hope you'll cooperate with my work...” 272

Trivia

• Momoshiki's failed takeover is compared to the earliest, hostile form of Tailed Beast sealing, specifically the Nine-Tails' initial imprisonment within Mito. 272
• Blue B's and Izuna's similar appearances and identical stance cause Izuna to experience a sense of déjà vu while they watch Momoshiki struggle. 272
• After the sealing, Blue B privately notes that Momoshiki's presence means he no longer needs to fear being ambushed by Shio and Tomie. 272
• Aosui was present with Danzo during a past battlefield crisis involving ten thousand Iwagakure and Kumogakure troops, from which Hiruzen rescued them while riding the Five-Tails. 274