Ten years after the deaths of Light Yagami and L, a world scarred by cyber-terrorism faces a chilling reemergence: unexplained deaths hint that Death Notes have returned to the living. Interpol assigns Ryuzaki, L’s biological successor, to lead the newly formed Death Note Task Force, which is quickly put to the test when a killer spree in Shibuya yields a crucial breakthrough: a notebook is secured as its owner, Sakura Aoi, is slain. Touching Aoi’s notebook, the team meets the original owner’s guardian, a Shinigami named Beppo, who reveals a startling bottleneck: there can only be six Death Notes in the human world at once. With this knowledge, the Task Force commits to locating the five remaining notes and stopping the spread of this deadly chain.
On the other side, the cyber-terrorist Yuki Shien vows to amass all six Death Notes, convinced he acts on a mission from Light via his Shinigami, Ryuk. Shien sows global panic by releasing a virus that features a video of Light as Kira, and reaches out to Light’s former ally, Misa Amane. Misa regains her memories of Death Notes and is gifted with Shien’s own notebook; she refuses to reveal Light’s hideout, having witnessed what she believes is Light’s supposed death years earlier. Undeterred, Shien uses extraordinary hacking skills to track three more Death Notes, eliminating their owners in the process. He impersonates Kira through another virus, threatening a killing spree unless L’s successor reveals his name and face.
In response, [Ryuzaki] spreads a CGI video of the original L, tempting Kira to visit a site designed to expose his location. Shien escapes just before killing one of the original Kira investigators, Touta Matsuda. Fearing that the investigation is compromised, the Japanese government dissolves the Death Note Task Force.
Mishima uncovers a hidden message in Ryuzaki’s video: “I own the last Death Note.” Angered, Mishima confronts Ryuzaki at his home and learns of the latter’s unconventional relationship with his Shinigami, Arma. Ryuzaki reveals that his own Death Note is blank, having promised L before his death that he would never use one. As Mishima leaves, he’s arrested on suspicions of compromising the investigation, but a year earlier he had been tasked with locating Light’s son and his secret successor, who ended up in the care of prosecutor Teru Mikami. Mikami and the boy vanish, leading police to suspect Mishima of conspiring with Kira. After questioning, Ryuzaki frees him so he can access the Task Force’s Death Note and help confront the new Kira. Mishima agrees to meet Shien at the National Arts Centre, while Mishima stays behind to guide the rest of the team.
When the plan unfolds, Shien lures the team with the promise that Ryuzaki will reveal his face and the Death Notes in their possession. The moment arrives, but a jamming signal cuts the line, forcing the team to reveal their faces. Three Task Force members fall to Misa’s newly acquired Shinigami Eyes, which display a person’s real name and lifespan. Misa reveals Light is dead and writes his name in the Death Note before killing herself.
Realizing the impostor Kira is not the one who gave him the task, Shien commits to eliminating the real rival and seizes the chance to acquire Shinigami Eyes for himself by sacrificing half of his lifespan. He aims to kill the impostor and claim the title of Neo Kira. In the brink of confrontation, Mishima and Ryuzaki confront Shien; Ryuzaki suspects Mishima might be Neo Kira, and when Mishima touches Shien’s Death Note, memories flood back. He recalls witnessing Teru Mikami’s descent into madness and Mikami’s murder of [Hikari Yagami], then kills Mikami and assumes Light’s mantle as Neo Kira. Mishima later relinquishes ownership of the notebook and instructs Ryuk to pass it to Shien, believing the cyber-terrorist will locate the remaining Death Notes. A tense standoff escalates, and the police move in to kill all three—the trio is shot, and Shien falls. Mishima and Ryuzaki escape through an abandoned subway, only to be confronted by the last surviving Task Force member; Arma sacrifices herself to prevent Mishima’s capture, a blow that deeply unsettles Ryuzaki as they are finally cornered by the authorities.
Interpol ultimately halts Mishima’s execution order, and Mishima is taken into custody while Ryuzaki explains the fate of the six Death Notes. The dying Shinigami King had promised his throne to the Shinigami who found the next Kira, but with all six notes accounted for, human greed looms as the trigger for a future resurgence. As Ryuzaki departs, a postscript reveals that terrorists attack the notebook-bearing vehicle, destroying four notes and leaving two missing. With today’s date marking his own death, Ryuzaki proposes a swap of fates with Mishima—who reveals his real name, Ryo Nakagami, and walks away to face whatever comes next.
> Just as I planned.
