As the Straw Hat Pirates make their way to the idyllic island of Elegia, they are entranced by the captivating performance of the world-famous singer Uta. Her debut act, entitled "New Genesis," not only highlights her extraordinary talent but also reveals her past connection with Luffy. Uta, the adopted daughter of the legendary Shanks, shares a significant bond with Luffy, rooted in their meeting twelve years earlier when Shanks was stationed in Luffy's hometown—an event that marked the inception of Uta's rise to fame.
After her mesmerizing show, Uta demonstrates her powers by dispatching potential kidnappers with a simple tune, asserting her belief that she can create the world she envisions through the magic of music. She dreams of a society filled with joy and tranquility, which her audience, including Luffy and his crew, expresses skepticism toward. When Uta’s vision is met with resistance, her demeanor shifts dramatically. She imprisons all but Luffy under her spell, using her enchanting melody. Rescue comes from unexpected allies, as Trafalgar Law and Bartolomeo help Luffy evade his captivity.
The situation escalates when the World Government takes notice of Uta's extraordinary abilities, labeling her a serious threat to global order. As a response, [Marine Fleet Admiral Akainu] and his mighty convoy—comprising Admirals [Kizaru] and [Fujitora]—are dispatched to regain control and neutralize Uta's influence.
As Luffy and his comrades navigate the chaos, they encounter Gordon, Uta’s adoptive father and former king of Elegia. Gordon reveals that Uta's sheltered upbringing was designed to protect her from the darkness of the outside world. However, as Uta achieved worldwide fame, she became aware of the suffering caused by pirates, compelling her to vow to eradicate the Pirate Era.
In a tumultuous turn of events, Uta appears again, forcing Luffy's group to flee while Gordon begs her to reconsider her destructive intentions. Yet, Uta remains unwavering, driven by the discovery of an ominous song called "Tot Musica," which possesses the power to reshape reality. She immobilizes Gordon while fixating on her ambition to create a new world.
The revelations escalate as Luffy’s crew stumbles upon a covert operation led by the World Government. They learn from Koby that Uta wields the remarkable ability granted by the Sing-Sing Fruit, which allows her to transport her audience into a dreamlike dimension known as the Sing-Song World. This illusionary realm, a product of her singing, ceases to exist whenever she sleeps—a precarious situation as it places all who enter at risk. The wake-shrooms that Uta consumes offer a temporary solution to her sleepwalking but drain her life force, presenting an imminent threat: should Uta perish, the dream world will take permanent hold of its inhabitants.
Meanwhile, the Marine fleet arrives at Elegia, only to discover the concert attendees incapacitated in a deep slumber. Their attempts to counter Uta’s seductive singing fail miserably as she deftly seizes control of the entranced crowd, launching a devastating sonic attack on the Marines. The Five Elders understand that Uta's life hangs by a thread, and her death could trap a staggering 70% of the world's population within the Sing-Song World. Resolute, Koby rallies his group to guide the pirates in song, enabling their escape from Uta's enchanting prison. As the Straw Hats make their way to the castle, they search for Uta's vulnerabilities amidst the unfolding chaos.
In the serene quiet of the library, [Robin] uncovers an ancient manuscript that holds the secret to merging the real world with the Sing-Song World—identifying Tot Musica as an ancient entity whose defeat is essential to free the trapped souls. As Uta continues her performance within the dream realm, the audience begins to reject the notion of eternal life in this fantastical purgatory. Haunted by her slippery grip on reality, Uta transforms her listeners into lifeless statues.
Fierce determination drives Luffy to confront Uta once more, where she drops a shocking revelation: Shanks abandoned her, allegedly destroying Elegia in the process. Betrayed and consumed by anger, Uta resolves to eliminate Luffy, but the sudden entrance of Shanks and his crew disrupts her plans.
Amidst battle cries, Akainu orders a devastating barrage toward Uta, forcing Shanks and his crew to defend her. As chaos ensues, Uta's psyche unravels, and the effects of the wake-shrooms push her into a delirious state, awakening Tot Musica. This ancient, malevolent force re-emerges, prompting memories of destruction Uta inadvertently unleashed upon Elegia twelve years ago.
Caught in the turmoil, both pirates and Marines are blindsided by Uta's connection to Tot Musica. In a desperate bid to quench the rising storm, Luffy faces the embodiment of ancient chaos while [Usopp's] steadfast resolve paves the way for a unique connection between father and son through Observation Haki. This connection allows them to synchronize their attacks across dimensions, launching a conclusive offensive against Tot Musica.
In a breathtaking climax that tests the limits of both realms, Luffy and Shanks successfully defeat the ancient menace. Though the inhabitants of Elegia are still enshrined in the Sing-Song World, Uta’s unwavering desire to reconnect with her audience drives her forward. Instead of accepting Shanks' offer of a remedy, she seeks to channel the very powers that afflict her to compose a song capable of reconnecting with those lost in Elegia. As the Marines attempt to restrain Uta, Shanks intervenes, commanding respect with his Conqueror's Haki, forcing them to retreat in disorder.
In the aftermath, Shanks and Uta come to a profound understanding of their relationship as father and daughter. Meanwhile, Luffy awakens on the Thousand Sunny, realizing that his crew has already ventured beyond Elegia. Left with nothing but the sight of the Red-Haired Pirates' ship sailing away, he contemplates the heavy loss symbolized by the mysterious coffin aboard—potentially holding Uta’s lifeless form.
