"Death Note Relight 1: Visions of a God" compresses the entire first saga of the anime, culminating in the death of L. The narrative begins with Light Yagami finding the Death Note and establishing his reign as Kira. The film covers his initial killings, his first encounters with Ryuk, and the beginning of the investigation led by L. Key plot points are included, such as Light killing the FBI agents tracking him (including Raye Penber), and subsequently tricking and killing Raye's fiancée, Naomi Misora.
The central arc of the film involves Light joining the Kira investigation team to get closer to L, leading to their famous confrontations. It also includes the Misa Amane storyline, where she becomes the Second Kira and uses her Shinigami Eyes to aid Light. A significant portion covers the Yotsuba Group arc, where Light temporarily relinquishes ownership of the Death Note to prove his innocence, losing his memories in the process. He then works earnestly with L to catch the new Kira, Kyosuke Higuchi.
The climax shows Light regaining his memories by touching the Death Note after Higuchi's capture. With his master plan back in motion, Light manipulates the Shinigami Rem into killing L and his guardian, Watari, in order to save Misa's life. Rem turns to dust for intentionally extending a human's lifespan, and L dies of a heart attack, but not before seeing Light's triumphant, sinister smile, confirming his suspicions at the last moment. A new, non-canon scene is included showing Light later gloating over L's empty grave, cementing his victory and his complete descent into villainy. The film ends with Ryuk finishing his story, leaving the unnamed Shinigami to ponder what he has heard before heading to the human world himself.