A rare, original illustration by The Little Prince author Antoine de Saint-Exupéry has been discovered in Japan.

François d'Agey, the author's nephew, was among those at a media conference in Tokyo on Wednesday announcing the discovery.

Francois d'Agey, nephew of Antoine de Saint-Exupéry, displays the original drawing alongside a copy of The Little Prince in Tokyo Wednesday.
(Yoshikazu Tsuno/AFP/Getty)

"Seeing [the drawing] made me very happy," the 81-year-old d'Agey told the gathering of reporters.

The image depicts the businessman on the fourth star visited by the title character of Saint-Exupéry's beloved story. The man is so busy counting stars that he pays no attention to the philosophical little character.

Museum head did not realize drawing's value

Minoru Shibuya, who heads up the Ehon Museum Kiyosato in Tokyo's neighbouring Yamanashi Prefecture, said he purchased the drawing at a second-hand book fair in 1994.

The Ehon Museum showcases the work of illustrators and graphic designers from around the world.

Though Shibuya declined to reveal how much he paid for the drawing — which he said he believed to be an original the moment he saw it — he admitted he did not realize its value until last February.

Though the famed French author and aviator reportedly drew all the time, everywhere he travelled, it's rare to find his original illustrations.

Expert verified drawing, signature, paper

Japanese researcher and Saint-Exupéry expert Hiroyuki Nakamura verified the authenticity of Shibuya's drawing and was also on hand at Wednesday's conference.

On the back of the drawing, Nakamura discovered pencilled instructions about how to trim the image for the first edition of The Little Prince. The individual sheet also bears the same page number as the corresponding image in the original copy of The Little Prince held in New York.

In addition, the document features Saint-Exupéry's signature and is on the same onion skin paper he favoured for drawing.

The image will be displayed as part of an art exhibition at the Matsuya Ginza department store in Tokyo beginning April 25.

Translated, sold worldwide

First published in the U.S. in 1943, The Little Prince has been translated into a host of languages and sold upwards of 80 million copies worldwide.

On July 31, 1944, Saint-Exupéry went missing while flying a reconnaissance mission over southern France. He had been assigned to gather information about Nazi troop movements in the Rhone Valley.

In 2004, a group of French researchers confirmed that wreckage found off the coast of Marseilles was from the author's plane.