"The Pillow Book" is a zuihitsu essay (literally, "random jottings"), which is said to have been written by Sei Shonagon, a female writer who lived in the mid-Heian period.
『枕草子』（まくらのそうし）は、平安時代中期の女流作家、清少納言により執筆されたと伝わる随筆。