Satoru Fujinuma, a struggling manga artist in his late 20s, possesses an unusual ability called "Revival," which forces him to relive moments before tragic events occur, allowing him to prevent them. After being wrongfully accused of a crime, Satoru's ability activates, sending him back in time to his childhood in 1988. This time leap coincides with the disappearance and murder of his classmate, Kayo Hinazuki, one of three victims in a series of kidnappings that haunted his hometown. Determined to alter the past, Satoru resolves to save Kayo and uncover the identity of the killer.

As Satoru navigates his childhood memories, he reconnects with friends and family, including his mother, Sachiko, who plays a pivotal role in supporting his efforts. Satoru's actions begin to change the timeline, but the killer remains elusive, and the stakes grow higher as he realizes the murderer is someone close to him. The narrative intertwines Satoru's attempts to protect Kayo with his own struggles to understand the true nature of his ability and its consequences.

The story explores themes of redemption, sacrifice, and the ripple effects of small actions. Satoru's journey is marked by moments of tension and emotional weight as he confronts the fragility of life and the burden of responsibility. The series balances its mystery elements with character-driven drama, delving into the lives of those affected by the tragedies and the impact of Satoru's interventions.

Key characters include Kayo Hinazuki, a lonely and abused girl whose fate becomes central to Satoru's mission; Airi Katagiri, a coworker from Satoru's adult life who inspires him to confront his past; and Kenya Kobayashi, a perceptive childhood friend who aids Satoru in his investigation. The antagonist, whose identity is gradually revealed, adds a layer of psychological complexity to the narrative.

The series concludes with Satoru facing the consequences of his actions across timelines, ultimately leading to a resolution that ties together the past and present. The story's intricate structure and emotional depth make it a compelling exploration of time, memory, and the human desire to protect what matters most.