Miyo Sasaki is a spirited 14-year-old girl residing in the charming town of Tokoname, Aichi Prefecture. She faces a challenging relationship with her stepmother, Kaoru, who often complicates her daily life. Miyo harbors a crush on the dashing Kento Hinode, who seems oblivious to her affections and generally keeps his distance. In an unexpected twist of fate, Miyo encounters a mysterious mask seller who gifts her a magical Noh mask. This enchanted artifact grants her the ability to transform into a cat, adopting the persona of "Tarō." As Tarō, she seizes the opportunity to spend time with Hinode, providing company as he dives into the world of Japanese pottery and confides in her about his troubles. Deep down, Miyo yearns to reveal the secret that the beloved cat he adores is indeed the same girl he disregards.
One fateful school day, Miyo overhears a group of boys making disparaging comments about Hinode. Unable to restrain herself, she leaps from the school building to defend his honor, sustaining injuries in her daring act. Remarkably, this moment leads to a breakthrough in their relationship, as Hinode shows an unexpected kindness by escorting her to the nurse's office and sharing his lunch. Later that evening, while still in her feline form as Tarō, Miyo discovers that Hinode's family is on the verge of closing their pottery shop due to financial strain. Determined to bring him joy, Miyo decides to express her feelings in a heartfelt letter. However, her plans are thwarted when a classmate snatches the note and reads it aloud, leaving Miyo and Hinode humiliated. In a desperate attempt to save face, Hinode publicly declares that he hates her, urging her to keep her distance.
Heartbroken, Miyo believes that living as a cat by Hinode's side is a preferable fate to being human and unloved. As a result of her choice, her human face detaches, transforming into a porcelain mask. The mask seller seizes the opportunity to collect her face, claiming he will give it to a cat who dreams of becoming human. Meanwhile, Miyo’s friends and family, including Hinode, are desperately searching for her, and Hinode even confesses to Tarō that he does not truly despise Miyo and wishes to apologize for his earlier hurtful words. Trapped in her cat form, Miyo begins to lose her understanding of humans. She experiences regret over her decision, while Kinako, Kaoru's cat, acquires Miyo's human face and starts living her human life. Kinako is adamant about not returning the face, revealing that she wishes to prolong her own life as she nears the end of her existence, longing to bring joy to her owner.
In a brave move, Miyo follows the mask seller to a hidden island of cats, hoping to convince him to revert her to human form. Kinako, along her journey, comes to realize just how much Kaoru cherished her cat and undergoes a transformation in her feelings. She divulges the secret of the masks to Hinode, leading him to the island to rescue Miyo. Kinako bestows a cat mask upon Hinode, which turns him into a half-cat—his arms morph into those of a cat. However, their escape becomes convoluted as the mask seller captures both Kinako and Hinode, only to be liberated by Miyo and another feline who once was human.
The mask seller brings Miyo and Hinode to the "promised place," where he intends to finalize their transformations by drawing upon their lifespans. However, his scheme is disrupted by a legion of disgruntled humans he once transformed into cats. As they make their way back to the human realm, Hinode repents for his past remarks towards Miyo and reciprocates her feelings, finally agreeing to become her boyfriend. Kinako, showcasing her change of heart, returns Miyo's face, restoring her to her original form.
In the heartwarming credits, we witness Miyo sharing the delightful news of Hinode's blossoming love with her friend, while Hinode confides in his mother about his future aspirations in pottery. The scene concludes with Hinode playfully executing Miyo's signature "Hinode sunrise attack," capturing the essence of their newfound connection and joyous adventure together.
