Based on the manga with the same title, this animated film follows Shizuku, an inquisitive young girl and a voracious reader, who longs to be a writer when she grows up. One day she notices that all of her library books have previously been taken out by one Seiji Amasawa. Amid chasing after a large cat, befriending an eccentric antiques dealer and writing her first novel, Shizuku aims to find this mysterious boy who may well be her soul mate.