Naomi Katagaki, a reclusive high school student with a passion for literature, grapples with social anxiety and indecision. His quiet life shifts when he bonds with Ichigyou Ruri, a similarly introverted classmate, over their shared love of books. Their tentative friendship blossoms into mutual affection, but tragedy strikes when a lightning strike during a fireworks festival leaves Ruri comatose, shattering Naomi emotionally.

Haunted by guilt, Naomi dedicates the next decade to reviving Ruri through the ALLTALE quantum storage system. His obsession consumes him: he neglects health, abandons relationships, and fixates on manipulating ALLTALE’s simulated realities. Repeated failures deepen his isolation, trapping him in cycles of desperation and dwindling hope.

Now an employee at the ALLTALE Management Facility, Naomi crafts an audacious plan. He creates an avatar to mentor his younger self within recorded timelines, steering past events to avert Ruri’s accident. This manipulation strains the system’s stability, triggering safeguards against his temporal interference. Undeterred by ethical quandaries and existential risks, he presses forward, clinging to memories of Ruri’s smile.

His relentless pursuit fractures his psyche. Failed simulations trigger breakdowns; rare interactions with colleagues underscore his disconnect from reality. A brief respite comes when caring for a stray cat—a fragile tether to the present—until authorities remove it, reigniting his despair.

In the end, Naomi chooses self-erasure to cement Ruri’s survival in a rewritten timeline. This sacrifice transforms his desperation into resolve, accepting oblivion to secure her future. The altered data ripples across realities, intertwining their fates in an unresolved loop where past and present collide—leaving open whether either timeline grants peace, or perpetuates their longing.