In 2026, while working in Japan, she accidentally saw a girl's name in an old information collection recording unsolved cases in Heisei.
Shiraishi Mio, seventeen years old.
He was murdered in early 1993 and the case remains unsolved.
When she opened her eyes again, she returned to the autumn of 1992, had a Japanese name "Kanzaki Aoi", and became a student in a high school in Kanagawa Prefecture.
And Shiraishi Mio was sitting in front of her.
It was less than half a year since the murder.
Kanzaki Aoi knows what happened in the future, but she doesn't know who the murderer is; she remembers the ending, but can't find the way to it.
In order to change Mio Shiraishi's fate, she began to investigate the case that had not happened yet.
However, as time passed, she gradually discovered that it was more difficult to be a rational outsider than to pursue the truth.
The river embankment after school, the corridors of the old school building, the lunch boxes shared during lunch break, the warm yellow street lights in front of the tram stop in late autumn...
Those years that originally existed only in old photos gradually became real and vivid.
And fate is also quietly deviating from its original trajectory.
But Kanzaki Aoi doesn't know that when the truth comes to light, Mio Shiraishi's ending may not be the only one that needs to be rewritten.
Purpose: When fate is known in advance, do people have the courage to rewrite the predetermined ending? Cherish the encounters of the moment, protect the ordinary and precious daily life, and find the power to change the future through growth and choice.