Fourteen-year-old Shizuku Tsukishima is an inquisitive middle school student with a passion for reading and a desire to discover her own aspirations. During her summer break, she observes that many of the library books she borrows have been previously checked out by someone named Seiji Amasawa. Her curiosity piqued, Shizuku becomes determined to find out more about this mystery person. She stumbles upon an antique shop owned by a kind, elderly man named Nishi, where she encounters a peculiar cat statue known as "The Baron."

Drawn further into the world of this antique shop and the mysterious Seiji, Shizuku eventually meets him and learns of his dream to become a master violin maker. Inspired by Seiji’s dedication to his craft, she decides to pursue her own talents, despite feeling uncertain of her abilities. Throughout the journey, Shizuku learns valuable life lessons about perseverance, self-discovery, and the importance of following one's heart. The film beautifully weaves together themes of young love and personal growth, set against the backdrop of a vibrant and bustling Tokyo.