Esaka's original story centers on Kurumi, a girl who grew up in an institution, and is excited on the eve of her 10th birthday, when her vocation will be announced to her. But when she awakens, she is already 22 years old, and she is somehow living with Kiyoka, a friend with whom she did not get along too well in the past. She finds out that on the day of her 10th birthday, she had an accident, and she began to suffer from a condition that only lets her hold memories one day at a time, and that 12 years had passed since then.

(Source: Anime News Network)