Lili died on the way to deliver food - she was hit to the ground by a Mercedes-Benz that was traveling in the opposite direction, and was crushed to pieces by an oncoming truck.
When she opened her eyes again, Lili was sitting in a familiar classroom.
This classroom was very much like the classroom in her memory. She didn't know if she had gone back to the past and started walking around, or if she had traveled through time.
When the system's mechanical sound sounded, Lili finally understood that she had traveled through time.
Intention: When school becomes an endless hell