Steins;Gate 0

In this dark, previously untold chapter of Steins;Gate, we follow the eccentric mad scientist Okabe as he grapples with the aftermath of his unsuccessful attempt to save Kurisu. In his struggle to move on, he decides to abandon his vibrant scientist persona and tries to forget the past. Just when life seems to return to normal, he encounters someone connected to Kurisu, who reveals that they are experimenting with a device capable of storing human memories and creating a simulation of the person, complete with their traits and personality. As Okabe begins to test this device, he discovers that the simulation of Kurisu not only revives his old pain but also introduces new, unforeseen tragedies.

Zero serves as a side story that delves into the future events of the Beta Attractor Field, which play a crucial role in making the conclusion of the original narrative possible.