More generally, a pillow book is a collection of notebooks or notes which have been collated to show a period of someone or something's life. In Japan such kind of idle notes are generally referred to as the "zuihitsu" genre. Other major works from the same period include Kamo no Chōmei's "Hōjōki" and Yoshida Kenkō’s "Tsurezuregusa". "Zuihitsu" rose to mainstream popularity in the Edo period, when it found a wide audience in the newly developed merchant classes. Furthermore, it gained a scholarly foothold, as Japanese classical scholars began customarily writing in the "zuihitsu" style. Reputable authors from this movement include Motoori Norinaga, Yokoi Yayu, and Matsudaira Sadanobu.