Chronos Ruler

Time is described as something powerful, empty, and unforgiving: it cannot simply be stopped, but perhaps it can be turned back. Koyuki, the main character, is injured while saving a child from a car accident and can no longer dance with her friends. Watching them prepare for their performance hurts, and Koyuki is tempted to return to the past and change what happened. But even if she could turn back time, would doing so be worth it? The story asks whether a past changed, however painfully, can truly be set right.