Greyfriars Bobby and Tokyo Hachiko

I never knew about Greyfriars Bobby until recently.

Greyfriars Bobby was "a Skye Terrier who became known in the 19th-century in Edinburgh and Scotland after reportedly spending fourteen years guarding his owner's grave, until his own death on 14th January 1872. belonged to John Gray, who worked for the Edinburgh City Police as a night watchman, and the two were inseparable for approximately two years.[1] On 15 February 1858 Gray died of tuberculosis. He was buried in Greyfriars Kirkyard, the graveyard surrounding Greyfriars Kirk in the Old Town of Edinburgh. Bobby, who survived Gray by fourteen years, is said to have spent the rest of his life sitting on his master's grave. A more realistic account[citation needed] has it that he spent a great deal of time at Gray's grave, but that he left regularly for meals at a restaurant beside the graveyard, and may have spent colder winters in nearby houses.
In 1867 when it was pointed out that an owner-less dog should be destroyed, the Lord Provost of Edinburgh, Sir William Chambers (who was also a director of the Scottish Society for the Prevention of Cruelty to Animals), paid for a renewal of Bobby's licence, making him the responsibility of the city council.
Bobby died in 1872 and could not be buried within the cemetery its+B51elf, since it was consecrated ground; instead, he was buried just inside the gate of Greyfriars Kirkyard, not far from John Gray's grave."

This is the statue of Greyfriars Bobby in Edinburgh, Scotland.

Tokyo Hachiko was "brought to Tokyo by his owner, Hidesaburō Ueno, a professor in the agriculture department at the University of Tokyo. During his owner's life Hachikō saw him off from the front door and greeted him at the end of the day at the nearby Shibuya Station. The pair continued their daily routine until May 1925, when Professor Ueno did not return on the usual train one evening. The professor had suffered a stroke at the university that day. He died and never returned to the train station where his friend was waiting.
Hachikō was given away after his master's death, but he routinely escaped, showing up again and again at his old home. Eventually, Hachikō apparently realized that Professor Ueno no longer lived at the house. So he went to look for his master at the train station where he had accompanied him so many times before. Each day, Hachikō waited for Professor Ueno to return. And each day he did not see his friend among the commuters at the station.
The permanent fixture at the train station that was Hachikō attracted the attention of other commuters. Many of the people who frequented the Shibuya train station had seen Hachikō and Professor Ueno together each day. They brought Hachikō treats and food to nourish him during his wait.
This continued for 10 years, with Hachikō appearing only in the evening time, precisely when the train was due at the station."

This is the statue of Hachiko at Tokyo's Shibuya railroad station

Do I have to add anything more? Well, please don't dimiss them as  "Black Swan".