The story shifts its focus to Tsubasa Hanekawa, the class president and academic genius who has always seemed to know everything. For the first time, the narrative is told from her perspective rather than that of Koyomi Araragi. The setting is a town where supernatural oddities manifest from emotional turmoil, and the story takes place several months after the events of Nekomonogatari Black.

As the new semester begins, Hanekawa encounters a gigantic, spectral white tiger on her way to school. That same day, her house burns down in a mysterious fire. Forced to find places to sleep, she first stays in an abandoned cram school, then accepts the reluctant hospitality of her rival, Hitagi Senjougahara. A pattern quickly emerges: each building where Hanekawa spends the night is systematically destroyed by the tiger, which calls itself Kako.

The core of the conflict lies within Hanekawa herself. She lives in a profoundly broken home where her parents are strangers sharing the same roof; they maintain three separate sets of cookware and never eat together. To cope with this loneliness and the pressure of being perfect, Hanekawa has spent years suppressing her genuine emotions—particularly her jealousy and her unrequited love for Araragi. This repression is what originally created the violent "Black Hanekawa" cat oddity. Now, her continued refusal to accept her own feelings has accidentally given birth to the white tiger, an oddity that acts on her hidden stress by burning away the places that represent her lack of a true home.

Unable to find Araragi, who is absent dealing with his own crisis, Hanekawa reluctantly accepts help from others. Senjougahara, suspicious of Hanekawa’s feelings for her boyfriend, offers her home and a sharp, analytical perspective. Araragi’s younger sisters, Karen and Tsukihi, also provide shelter and a chaotic, energetic contrast to Hanekawa’s stoicism. As the tiger destroys each temporary refuge, Hanekawa is forced to confront the darkness she has kept bottled up inside.

The climax occurs when the white tiger prepares to burn down Senjougahara’s apartment. Hanekawa realizes that she cannot exorcise the tiger through force or intellect alone; she must accept the ugly, jealous, and selfish parts of herself that created it. In a moment of emotional catharsis, she acknowledges her feelings of romantic jealousy toward Senjougahara and admits she is tired of being "perfect." Araragi arrives at the last moment and uses his mystical blade, Kokorowatari, to sever the tiger from its host.

In the resolution, Hanekawa finally confesses her love to Araragi. He gently rejects her, reaffirming his commitment to Senjougahara. For the first time, Hanekawa does not suppress the pain of this rejection. By accepting her heartbreak, she absorbs the white tiger into herself, which permanently leaves white streaks in her hair. The story ends with her returning to a slightly improved home—where she now finally has her own room—signifying that she has stopped running from her reality and has begun the process of truly living with her own flaws.