Whisper of the Heart follows Shizuku Tsukishima, an energetic 14-year-old who spends her free time reading and writing poetry. One evening, while checking the library cards in the books she has borrowed, she notices the same name appearing over and over: Seiji Amasawa. Intrigued by the boy who seems to share her love for literature, Shizuku sets out to find him, hoping to learn who he is and why their paths keep crossing.
Her search leads her to a peculiar cat on a train and, from there, to a quaint antique shop where she discovers a cat statuette known as The Baron. There she finally meets Seiji, and the two quickly become friends. As Shizuku learns that Seiji has a dream he is determined to pursue, she is forced to confront her own uncertainty. Talented and restless, she has not yet decided what she wants to become, and that uncertainty leaves her uneasy.
As their bond grows, Shizuku finds herself inspired to take her own future seriously. Guided by the whispers of her heart and the quiet promise of The Baron, she begins to search for her own potential and to shape a dream she can call her own.