The other day I saw a picture of a dead dog on Twitter. Gross, right? Not at all, for this wasn't just any old dog: This was Hachiko, perhaps the most famous dog in the world, and certainly the most famous in Japan.

The tweet announced that it was the last photo ever taken of Hachiko. He is shown lying on a pallet, surrounded by the staff of Shibuya Station and his owner's wife. It is 1935, and every day for the last 11 years Hachiko has been turning up at Shibuya Station to meet his master, a University of Tokyo professor called Hidesaburo Ueno. But unbeknownst to the dog, the professor died in 1925, so for 10 of those years Hachiko has waited in vain.

Even when he was alive, Hachiko was a famous dog. People would come to see him, pat him and give him treats. But when he died (of cancer, not from a yakitori skewer as some legends have it), the fame just got bigger. A year before his death, a statue was erected outside the station in his honor.