Shizuku Tsukishima is a 14-year-old student at Mukaihara Junior High School, where she is best friends with Yūko Harada. She lives in Tokyo with her parents Asako and Seiya and older sister Shiho, and is keen on creative writing. One evening, she looks through the checkout cards in her library books and discovers they were all checked out previously by someone named Seiji Amasawa.
Over the next few days, she encounters a boy who annoys her by teasing her about “Concrete Roads”, a set of original lyrics describing Tama New Town that Shizuku based on the song “Take Me Home, Country Roads”. Finding a cat riding a train, Shizuku follows it to discover an antique shop run by Shirō Nishi. In the shop is a cat statuette nicknamed The Baron. Shizuku is ecstatic about finding “a place where stories begin”.
Shizuku later encounters the boy again at the antique shop. He shows her the workshop, where she discovers that he is learning to make violins to pursue his dream of becoming a master luthier. She begs him to play the violin for her, but he agrees on the condition that she sings along. The pair perform “Take Me Home, Country Roads”. The boy is revealed to be Seiji, Nishi’s grandson, and Shizuku and Seiji finally befriend each other.
Seiji admits that he admires Shizuku’s talents and that he had been checking out a large number of books in the hopes that she would eventually notice him. Days after, Seiji leaves for Cremona, Italy for a two-month study with a master violin-maker. Inspired by him pursuing his dream, Shizuku decides to pursue her writing seriously during the two months. She asks Nishi if she can write a story featuring the Baron, to which Nishi grants his consent in exchange for being the first to read her story.
Shizuku concocts a fantasy story featuring herself as the protagonist, the Baron as the male hero looking for his lost love, Louise, and the cat from the train (a neighborhood stray who is, among other names, known as “Moon” and “Muta”) as the antagonist. Devoting her time to her writing, Shizuku stays up until early in the morning, and her school grades drop. She argues with her family over her grades and future. As she continues to push herself, her anxiety mounts.
When her story is complete, Nishi reads it and gives his honest assessment. Shizuku bursts into tears as the stress of the last two months turns into relief. Nishi consoles her and tells her the real-life story of the Baron. When he studied in Germany in his youth, he found his first love, a woman named Louise. Nishi discovered the twin statuettes of the Baron and his female companion in a cafe, but as the female one was away for repairs, the shopkeeper would only allow Nishi to buy the Baron if Louise agreed to hold onto its companion so they could be reunited. However, the two lovers and their cat statues were separated during World War II.
Deciding she needs to learn more about writing, and that she wants to attend high school, Shizuku announces to her mother that she will resume studying for her high school entrance exams. The next morning, she wakes up and sees Seiji outside on his bicycle, having returned a day earlier. In the English dub, Seiji tells Shizuku he decided to finish high school before returning to Cremona to become a luthier, differing from the Japanese dialogue, in which he says he will return to Cremona after middle school graduation as planned.
The two ride Seiji’s bike to a lookout and watch the sunrise, where Seiji professes his love for Shizuku and proposes that they marry in the future; she happily accepts.