The film's title, "The Pillow Book" is a reference to an ancient Japanese diary written by Sei Shōnagon. The film is narrated by Nagiko, a Japanese model living in Hong Kong, Nagiko seeks a lover who can keep up with her sexual appetites as well as her appreciation for poetry and calligraphy. Her fetish for poetry and calligraphy is born from her father’s practice of writing characters of virtue and good fortune on her face with a brush during her birthday.
Nagiko eventually learns that her father is in bondage to an enigmatic Yaji-san, his publisher, who prints and circulates her father’s work in exchange for sexual favors and near total control over all the decisions that her father makes---including the choice for her future husband. Yaji-san arranges for his apprentice to marry Nagiko.
Their union is anything but happy however as her husband is actually bitter towards Nagiko, resentful at having been pressured to marrying her and disdainful of her mania for literature, ironic given his apprenticeship to a publisher. He refuses to have sex with her and refuses her body-writing fetish to her frustration. Their conflict comes to a head when her husband discovers and reads Nagiko’s diary where she logs her insights and sexual exploits. Livid, he burns the diary and this spurs Nagiko to leave him permanently.
She relocates for Hong Kong where she finds work as a secretary. Hong Kong is a turbulent place and Nagiko is finds herself witnessing student protests frequently. The work she does as a secretary, typing out memos for a Japanese fashion designer, is work that she finds distasteful as she despises the typewriter as the anathema of calligraphy. Nagiko’s employer eventually makes her one of his models and she earns acclaim as a fashion model. Along with her new wealth as a model come a string of lovers, many of them disappointing as they are either lousy in bed or but great in calligraphy or the reverse.
She runs into a British translator, Jerome, who works at the consular office in Hong Kong. Her curiosity is piqued by his knowledge of languages so she invites him over to have him write on her skin. She is repulsed by his handwriting however and she proceeds to dismiss him when he turns the table on Nagiko offering his body as a blank canvass to write on. Shocked at the reversal she backs out and runs out on Jerome, her ears ringing with his laughter.
Nagiko, intrigued by Jerome’s proposal, has a string of one-night stands where she experiments on writing on the bodies of her lovers. One of her lovers, Hoki, a Japanese photographer and student activist hopelessly smitten with Nagiko, begs her to take him as a lover. Nagiko turns him away however explaining that his skin is unsuitable for her calligraphy fetish, as the ink doesn’t dry properly, smearing and rendering her work incomprehensible. Hoki tries to keep her interested in him by suggesting she write a book instead, offering to take it to a famed publisher he does work for occasionally. Nagiko enthusiastically agrees to write the book and Hoki promptly takes it to the publisher. Nagiko’s manuscript is rejected however with some insulting words thrown in for good measure. She is shocked to discover that the mysterious publisher is none other than Yaji-san, her father’s predatory old publisher. In addition to this twist of fate she also learns that Jerome is Yaji-san’s lover too.
She hatches a plan to get back at Yaji-san using Jerome as leverage. In meeting up with Jerome again though she is pleasantly surprised to find out that he has not only learned some new languages but his skill with the brush has also improved considerably. They spend a considerable amount of time writing on each other and making love and Nagiko realizes that she has finally found the perfect lover in Jerome. She discloses the truth to Jerome about her plot to get back at Yaji-san for all the grief he has caused her family. Jerome however suggests a twist that is sure to hook the old publisher in: Nagiko will write her book on his skin and take it back to Yaji-san and that she will keep her identity anonymous. The ploy works and the old publisher has the text copied from his naked body. Jerome however dallies with the old publisher not returning to Nagiko prompting her to search for him. When she finds him having sex with Yaji-san she takes this as treachery and hatches an elaborate plot to take vengeance on them both.
Nagiko strings together five lovers of various nationalities and walks of life to serve as living canvasses for each chapter of her book that she then commands to go to the publisher. Her plan succeeds: Yaji-san is enthralled with the text and unorthodox method of delivery and Jerome is inflamed with jealousy but Nagiko refuses to give him the time of day. Jerome falls into a deep depression and meets up with Hoki to find out a way to get Nagiko back. Hoki suggests that he feign his death ala Romeo and Juliet as a last ditch attempt to win her back. Jerome takes his advice but overdoses on the pills and ends up dying. Nagiko is crushed, realizing how deeply she actually loved him. She repentantly pens the 6th chapter on his corpse, but Yaji-san arranges to have the body exhumed and flays the skin with the text to make a macabre “pillow book” for himself. Nagiko returns to Japan and there learns about what has been done to Jerome’s remains. Outraged, she writes Yaji-san anonymously demanding that he surrender his pillow book to her and in return she will give the remaining chapters of her book. He agrees to the trade, as he is now fanatical about the mystery author’s work.
She strings together seven more individuals and sends the chapters piecemeal like the first five, each individual bearing a clever twist on the location of the text based on the subtitle of chapter. Nagiko also finds out that she is pregnant with Jerome’s child. The last chapter of the book is written on the massive cadaver of a sumotori, and here she finally reveals her identity as well as the depth of the knowledge of his crimes against her family and Jerome. Yaji-san is aware of how damaging the information Nagiko holds can be once it becomes public so he surrenders his copy of chapter six, written on Jerome’s skin, then choses to have himself killed rather than be blackmailed. Nagiko buries chapter six and shortly after gives birth to Jerome’s child where she continues the practice of writing calligraphy on her child’s face.
