The tragedy of Tenjin Elementary School will happen again, but the stage will be different.
"Human beings are full of sorrow and resentment. As long as they are pushed a little, they will be doomed. Foolishly, they want to cover it up, but they can't escape the consequences." Sachiko
This is an era where time travel is like a running dog. What will happen when Sachiko, the resentful ghost, travels through time?