"Yowa no Nezame" is a story of the ocho monogatari (tales of the Heian and Kamakura periods) written in the latter half of the Heian period (supposedly around the latter half of 11th century).
『夜半の寝覚』（よわのねざめ）は平安時代後期（11世紀後半ごろか）に成立した王朝物語の一。