One day a puppy comes to the house of Akari, who has just turned twelve, and was trying hard to act strong after her mother suddenly fell ill. She immediately falls in love with the puppy and names it "Socks" after the paws which looked like they had white socks on. Akari was together with Socks day and night. Wherever Akari would go, Socks will follow. Akari would take care of Socks, and also Socks heeled Akari's sadness to recover from her mother's death. However, as Akari grows up, her feelings and interest moves away from Socks. Year by year, their distance grows, which also leads to her physical distance as she moves to a far off city, and must leave Socks behind to a childhood friend. One day Akari remembers the 10 promises that she had made with Socks (and her mother)---