A missing chapter of the oldest copy of Japan’s Tale of Genji – often referred to as the world’s first novel – has been discovered in storage at a home in Tokyo.

The centuries-old manuscript, which contains the fifth chapter of Japan’s most famous work of literature, has been authenticated as the oldest in existence by experts.

The discovered text dates back as early as the 12th century and is thought to have been transcribed by the poet Fujiwara Teika, according to local media reports.

The Tale of Genji is an epic three-part oeuvre spanning more than 1,100 pages and 54 chapters, understood to have been written by the 11th century noblewoman and lady-in-waiting Murasaki Shikibu.

The work – known as Genji Monogatari in Japanese – depicts colourful tales surrounding the romantic life of the son of a Japanese emperor, illuminating the intimate workings of Imperial court life in Kyoto over 1,000 years ago.

The missing manuscript was reportedly uncovered inside a large chest in the storeroom of a home in Tokyo belonging to Motofuyu Okochi, 72, an ancestor of a distinguished feudal lord.

The manuscript – which measures 21.9cm by 14.3cm – is thought to have been in the family’s hands for centuries. Old manuscripts of four other chapters within the same section of the novel were reportedly discovered in the 1930s and are designated as important cultural properties by the Japanese government.