The Girl Who Leapt Through Time is hands down one of my favorite animated movies of all time. So how could I not talk about it.
TGWLTT follows teenage space case Makoto Konno and day to day mishaps. After an accidental fall in the school science lab she finds a walnut shaped item which passes on the ability to Time Leap. (Which she learns after a near death experience) Makoto swiftly takes advantage of her newly found gift but later learns that her choices have repercussions.