Who is the New Upper Moon 4 in Demon Slayer? Explained

Eye of the Upper Moon 4
Eye of the Upper Moon 4 (Image Source: Studio Ufotable)

Demon Slayer's hierarchy of evil just underwent a deadly transformation. The biwa strings echo through the Infinity Castle as Muzan Kibutsuji reshuffles his most dangerous subordinates. A silent, pale figure now sits among the Upper Moons, her single eye gleaming with the kanji marking her new rank.

The new Upper Moon 4 is Nakime, the mysterious biwa-playing demon who controls the dimensional Infinity Castle. She climbed to this position after Hantengu's death during the Swordsmith Village Arc. Unlike her precursors, Nakime's potency lies not in raw combat power but in her ability to control entire battlefields and assemble critical intellect for the Demon King's last attack.

Hantengu, the former Upper Moon 4, was eventually defeated by Tanjiro Kamado during an extended battle in the Swordsmith Village Arc of Demon Slayer. His death formed a vacancy in the Upper Moon ranks that Muzan needed to fill strategically. Unlike the last replacements within the Twelve Kizuki, Nakime's upgrade wasn't based only on combat prowess but on her unique abilities and unflagging devotion.

Nakime as seen in the series (Image Source: Studio Ufotable)
Nakime as seen in the series (Image Source: Studio Ufotable)

Nakime had been functioning under Muzan long before her official rise to Upper Moon 4. Her role as the caretaker and controller of the Infinity Castle made her priceless to Muzan's operations. The biwa-playing demon had already proven her worth by summoning Lower and Upper Moons for meetings and fostering Muzan's strategic movements.

Nakime lived as an impoverished musician in the Demon Slayer series, stuck in a difficult marriage to a man addicted to gambling before she became a demon. Her transformation began after an attempt on Muzan’s life. Instead of killing Nakime, Muzan was impressed by her tracking abilities and spared her life, choosing to turn her into one of his most loyal servants.

This origin story reveals the reason why Nakime possesses such extraordinary loyalty to Muzan. Unlike other demons who serve out of fear or ambition, Nakime's devotion stems from genuine admiration for the Demon King's power.


Unique Abilities and Enhanced Powers in Demon Slayer

Nakime as seen after becoming the Upper Moon 4 (Image Source: Studio Ufotable)
Nakime as seen after becoming the Upper Moon 4 (Image Source: Studio Ufotable)

Nakime’s powers allowed her to control a strange, otherworldly space called the Infinity Castle, which appears endless to those inside. Her Blood Demon Art centers around manipulating this vast dimensional fortress using her biwa instrument. By strumming the strings, she can rearrange rooms, create passages, and transport individuals anywhere within the castle.

By playing her biwa, Nakime can reshape the Infinity Castle at will, teleporting herself and others instantly. This ability enables her to split up enemies and isolate targets.

Following Nakime's promotion to Upper Moon 4, Muzan improved her abilities by giving her additional demon blood. This power boost gave her a new technique called Eye Detachment, permitting her to devise and control multiple eyeballs that can spy on prey from great distances.

Nakime is seen getting controlled in the manga (Image Source: Shueisha)
Nakime is seen getting controlled in the manga (Image Source: Shueisha)

No longer limited to passive support roles, she became an active intelligence gatherer qualified to track down the Corps' most secret locations. This result puts every member of the Demon Slayer organization at risk.

Nakime's advancement and enhanced abilities operate as the stimulus for Demon Slayer's climactic final arc. Her intelligence-gathering win gives Muzan the information he needs to launch his ultimate assault on the Corps.

As such, the new Upper Moon 4's unique skill set ensures that the final battle will be fought on terms favorable to the demons. Her control over the Infinity Castle means the Demon Slayers will be fighting on unfamiliar ground. This tactical disadvantage will test the limits of their training and determination.

Edited by Amey Mirashi