I always admire the work of the japanese animators! Their sories (in general) are very strange, full of fantasy but they hide pieces of truth and of course the distant future is very close to us which is something that fascinates me!
Time travel was always (and still is) a matter of discussion, reffering to the fact that maybe someday we will be able to do it. History will change dramatically and this is something we must be aware of.
But the story has to do with the good part and the innocence of a girl who cannot undestand why has the power to do it. Time will give her the chance to change her destiny, her life, her everything!
Classic anime, different from the others, don't miss a minute otherwise you will lose the meaning of the sory!