Which work of Japanese literature is sometimes referred to as the world’s first novel?

The Tale of Genji (Genji Monogatari), written by Murasaki Shikibu in the 11th century, is a unique depiction of the lifestyles of high courtiers during the Heian period. It was written in archaic language and a poetic and confusing style that make it unreadable to the average Japanese without dedicated study. It was not until the early 20th century that Genji was translated into modern Japanese, by the poet Akiko Yosano.