Chapter seven of Ma no Kakera.
Kyokumi Nanakuse (whose name means "Seven Habits" or "Seven Quirks" Kyokumi) is an admired author with a cult following, known for the addictive style of her writing. Kaori Koroketsu, who aspires to be an author, has become obsessed with Nanakuse and her books. Nanakuse is known for writing about habits and compulsions, and for giving her characters bizarre quirks. As time passes, Kaori becomes more and more obsessed with Nanakuse's work, to the point of neglecting other pursuits in her life including her own writing. She begins to wonder who the real Kyokumi Nanakuse is, and sends her a fan letter. To Kaori's shock Nanakuse replies with an invitation to meet her.
Kaori goes out to a secluded mountain area where Nanakuse apparently lives. Nanakuse's assistant Negishi comes to collect Kaori from the bus stop. Negishi warns that Nanakuse lives in an "eerie land", and that Kaori will be doomed if she enters. On arriving at Nanakuse's house, Kaori is shocked to discover that Nanakuse is biologically male. She expects Nanakuse to give feedback on her writing but Nanakuse screams and rages at her, calling Kaori mediocre and saying that she does not have enough quirks. Kaori is so terrified that she wets herself, and Nanakuse laughs at her.
After a while Nanakuse calms down and offers Kaori a very strong absinthe from her vast collection of drinks. Although it's too strong for Kaori, she is unable to stop herself from knocking back shots. She becomes more and more drunk, and tries to ask about her favourite line in one of Nanakuse's books, where a character claims that "there's only two kinds of people in this world: those with quirks and those with no quirks!" Kaori tells Nanakuse to stop pretending to be a woman, and pulls off Nanakuse's wig. She demands that Nanakuse acknowledge her as having quirks. Kaori collapses from drinking too much, and Nanakuse orders Negishi to throw Kaori into a dungeon under the house.
Nanakuse attends a dinner party with local residents who are delighted to have had her move to their area. Nanakuse says that she was attracted there because it is believed to be haunted, and the residents confirm that the village was a past site of executions and reported Satanic worship. Nanakuse begins to demonstrate bizarre movements such as shaking her head and sticking out her tongue; the others at the party are all compelled to imitate her.
Kaori awakes in the dungeon and sees that dozens of other people have been locked up there. Each of them displays a single, repetitive movement over and over. Nanakuse arrives and explains that they have all lost their sanity from being imprisoned for so long. They are reduced to an animal-like state and Nanakuse has waited for one of them to exhibit some kind of unique trait, but so far none have. Nanakuse expresses hope that Kaori will demonstrate a quirk for her to write about in her next novel. Kaori begins to scream and panic, eventually going insane from her surroundings and the repetitive movements of those around her. She feels her face and body going rigid, and begins to tear at her face.
Some time later, Negishi reports that Kaori has not been touching her food nor moved from the same position for three days. Negishi and Nanakuse enter the dungeon to find that Kaori has assumed a bizarre, outstretched pose facing the wall; but she has a pulse and is still alive. They discover that she is now incapable of movement and her face has hideously warped and mutated. Nanakuse is thrilled, and declares that it's the most extreme "quirk" she has ever seen. She is overcome with inspiration and writes a new book, Extreme Quirk, about Kaori.
Subsequently, Kaori is of no more use to Nanakuse and her body is given as a "present" to the local residents' association at another dinner party, where the guests are all compelled to imitate Nanakuse's impression of Kaori.