It is an illuminated manuscript of Yoru no Nezame (夜の寝覚, Wakefulness at Midnight), which recounts a romance at the Imperial Court in Kyoto.

The work is one of the oldest of the emakimono preserved today, as well as one of the few extant examples of the onna-e ("women's pictures") style of painting in the Heian period.

Originating in Japan in the sixth or seventh century through trade with the Chinese Empire, emakimono art spread widely among the aristocracy in the Heian period.

The themes of the stories were very varied: illustrations of novels, historical chronicles, religious texts, biographies of famous people, humorous or fantastic anecdotes, etc.

[1] During the Heian period, the illustrations of novels known as monogatari-e became very fashionable at court, contributing to the professionalisation and improvement of the art of emaki which reached its maturity around the second half of the 12th century.

[7] The paintings in the emakimono fit within the onna-e genre of the Yamato-e style fashionable from the 12th century to the end of the Heian period.

[8] Onna-e paintings are generally very stylized, elegant and refined, with rich, opaque colour used to represent the peaceful, romantic and often nostalgic atmosphere of the lives of the ladies at the Imperial Court.

[6][11] A first sketch of the scene is made in India ink, then the colour is applied in a precise order, from the large areas in the background to the final details, following the instructions of the master sometimes annotated directly on the paper.

It testifies to the refinement achieved by narrative court painting at the end of the Heian period, which heralds the golden age of the emakimono.