This is a 25-minute sprint through the manga's opening that moves so fast you're still catching your breath when it ends. The animation nails every panel, every expression, every moment of Yukiteru's spiral from invisible to hunted. It exists to prove the concept works in motion, not to stand on its own, and it absolutely does.
Yukiteru is a friendless middle schooler who finds solace in documenting his surroundings in his phone diary, treating the world like an observer would. His isolation is so complete that he's invented an imaginary companion: Deus Ex Machina, a godlike entity who claims dominion over time itself. When Deus decides Yukiteru's loneliness warrants intervention, he grants the boy an extraordinary gift. His diary no longer records the present, but the future, showing events that haven't yet unfolded. This power comes with a price. Yukiteru is conscripted into a deadly game where diary holders compete against one another, each entry a window into what's coming next. Victory promises a reward beyond imagination: the chance to become Deus's successor and reshape reality itself. What begins as an escape from loneliness transforms into a fight for survival where knowledge of tomorrow becomes both weapon and curse. This OVA serves as a prologue to a much larger conflict, introducing the premise that will drive the complete series forward.