At a dinner party in Gion, Abino, a 26-year-old geiko (regional term for geisha used in Kyoto), serves sake to Dr. Suda, a veterinarian. Her wealthy patron, Ioka, a building owner in Kyoto, explains that Dr. Suda helped him when an illegal cat breeder in one of his properties abandoned numerous cats. The breeding operation had failed, and the breeder fled, leaving the animals in critical condition. Dr. Suda treated the few survivors, helped clean the unit, and held a memorial service for the deceased cats. When Abino privately asks Dr. Suda about the rescued cats, he reveals only two survived and remain at his clinic because potential adopters are hesitant to take them in, given the cats’ traumatic past.

Days later, Abino visits Suda Animal Hospital to adopt one of the survivors. She encounters a young man named Kajiwara leaving with the other rescued cat, a black cat named Nikké. Dr. Suda presents Abino with the remaining cat, a two-year-old female calico with declining kidney function requiring lifelong care. Despite the warning, Abino feels an instant connection when the cat nuzzles her hand and agrees to adopt her. The cat has no name yet.

Abino lives at the Komano-ya okiya (a lodging house for geiko) with the proprietress, Shizue, and fellow geiko. Her cat, now named Chitose, has improved physically after a year of care but remains aloof. At Chitose’s monthly checkup, Dr. Suda reveals her condition has worsened despite ongoing treatment. Determined to save her, Abino requests a referral to a hospital offering advanced care. Dr. Suda agrees, warning of the cost and time commitment. That night, Chitose is unusually affectionate. Abino vows they will be together forever. Later, Abino wakes to find Chitose leaping through the window, vanishing into the moonlit streets of Gion.

Three months later, Abino is still searching for Chitose, putting up posters and checking shelters daily. She feels overwhelming guilt, believing she failed to lock the window. Dr. Suda tells her he views named animals as being inextricably paired with their owners and that decisions about Chitose’s welfare are between Abino and Chitose alone. Seeking closure, Abino visits the fifth-floor unit where Chitose was rescued. The space is spotless and empty, offering no comfort. She continues secretly visiting to call for Chitose.

A year after the disappearance, Abino picks up a custom bag from designer Tomoka Takamine. When Tomoka offers a cat-themed fob, Abino weeps, confessing her unresolved grief. Tomoka comforts her, mentioning a strange doctor and claiming the clinic’s door will open for those who genuinely wish to find it.

Wandering lost in thought, Abino finds herself at the Nakagyō Building. The door to the fifth-floor unit is unlocked. Inside, she discovers a clinic where a nurse who looks exactly like Abino greets her by her real name, Ami Takeda. The doctor is a man she recognizes as Kajiwara, the owner of Nikké. When Abino says her cat will not come home, the doctor replies they will prescribe her a cat and calls for the nurse, whom he addresses as Chitose. Abino receives a carrier containing Mimita, a five-month-old Scottish Fold, for a 10-day trial period.

Back at the okiya, Shizue and another geiko, Yuriha, are instantly smitten with Mimita, comparing his round appearance to a sweet rice ball. Abino resists bonding with him, feeling it would betray Chitose. She insists she must return him. That night, she continues to ignore Mimita despite his attempts to connect.

Near the end of the trial period, Abino arrives home to find Mimita has escaped onto the wet cobblestones. Terrified of losing another cat, Abino kneels before Mimita and tearfully apologizes for being cold, explaining her guilt over Chitose. Mimita approaches and allows her to pick him up. Inside, Abino and Shizue discover the window is open again. Abino realizes there is a mechanical fault with the latch. It was not her carelessness that allowed Chitose to escape. This lifts the burden of her guilt.

Yuriha begs to adopt Mimita, which makes Abino realize she isn’t alone in her grief over losing Chitose. Abino returns to the clinic to reassess her feelings. The doctor indicates that Mimita must be returned to the pet shop he was loaned from. The nurse tells Abino where to find the pet store. Speaking as Chitose, the nurse then gives Abino permission to move on, saying she left of her own volition. The doctor, also speaking from a cat’s perspective, advises Abino to let go and say goodbye, as she is holding onto Chitose’s tail and preventing them both from moving forward. Abino closes her eyes and wishes Chitose a heartfelt farewell. As she leaves, the nurse apologizes for not being able to stay with Abino forever. Abino calls Yuriha to go with her to the Kusatsu shopping mall to find Mimita. 

The scene shifts to Dr. Nikké, sitting alone in the clinic. The nurse, Chitose, enters and confirms they are a bonded pair who will continue their work prescribing cats. A new patient arrives, and Dr. Nikké smiles, saying they will prescribe her a cat.