Hachikō

Professor Hidesaburō Ueno took Hacikō as his pet in 1924, and they were inseparable. His dog would see him off to work every day, and be waiting at Shibuya Station everyday when he got home to run errands and return home with him.

But then in May of 1925 Professor Hidesaburō Ueno suffered a stroke while teaching and died. Despite being given to another caring family Hachikō would escape to return to the station to wait for his master to return.

Hachikō became a permanent fixture at the train station and the regular commuters brought him snacks and food to keep him nourished. He arrived everyday at precisely the time the train did for ten years until he died on March 8, 1935.

His stuffed and mounted remains are kept at the National Science Museum of Japan in Ueno, Tokyo. Several statues have been built in his honor, and 2 feature films.

He was also the inspiration for the Futurama episode "Jurassic bark" which is quite possibly the saddest thing ever animated. If case you haven't seen it, heres a clip:

You can read more on Hachikō here or on Wikipedia