Hachiko, a golden brown Akita, was born on November 10, 1923, at a farm located in Ōdate, Akita Prefecture, Japan.

In 1924, Hidesaburō Ueno, a professor in the agriculture department at the Tokyo Imperial University, took Hachikō as a pet and brought him to live in Shibuya, Tokyo.

Ueno would commute daily to work, and Hachikō would leave the house to greet him at the end of each day at the nearby Shibuya Station. The pair continued the daily routine until May 21, 1925, when Ueno did not return. The professor had suffered a cerebral hemorrhage, while he was giving a lecture to his class, and died without ever returning to the train station in which Hachikō waited.

Each day, for the next nine years, nine months and fifteen days, Hachikō awaited Ueno's return, appearing precisely when the train was due at the station.

One of Ueno's students, Hirokichi Saito, who developed expertise on the Akita breed, saw the dog at the station and followed him to the home of Ueno's former gardener, Kuzaboro Kobayashi, where he learned the history of Hachikō's life. Shortly after the meeting, the former student published a documented census of Akitas in Japan. His research found only 30 purebred Akitas remaining, including Hachikō from Shibuya Station. He returned frequently to visit Hachikō, and over the years he published several articles about the dog's remarkable loyalty. In 1932, one of his articles, published in Asahi Shimbun, placed the dog in the national spotlight.

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. Initial reactions from the people, especially from those working at the station, were not necessarily friendly. However, after the first appearance of the article about him in Asahi Shimbun on October 4, 1932, people started to bring Hachikō treats and food to nourish him during his wait.

In April 1934, a bronze statue based in his likeness sculpted by Teru Ando was erected at Shibuya Station. The statue was recycled for the war effort during World War II.

Hachikō became a national sensation. His faithfulness to his master's memory impressed the people of Japan as a spirit of family loyalty to which all should strive to achieve. Teachers and parents used Hachikō's vigil as an example for children to follow. A well-known Japanese artist rendered a sculpture of the dog, and throughout the country, a new awareness of the Akita breed grew. Eventually, Hachikō's legendary faithfulness became a national symbol of loyalty, particularly to the person and institution of Emperors.

Hachikō died on March 8, 1935, at the age of 11. He was found on a street in Shibuya.

Each year on March 8, Hachikō's devotion is honored with a solemn ceremony of remembrance at Tokyo's Shibuya railroad station. Hundreds of dog lovers often turn out to honor his memory and loyalty.

In 1948, Takeshi Ando (son of the original artist) made a second statue. The new statue, which was erected in August 1948, still stands and is a popular meeting spot. The station entrance near this statue is named "Hachikō-guchi", meaning "The Hachikō Entrance/Exit", and is one of Shibuya Station's five exits.

Yaeko Sakano, more often referred to as Yaeko Ueno, was an unmarried partner to Hidesaburō Ueno for about 10 years until his death in 1925. Hachikō was reported to have shown great happiness and affection towards her whenever she came to visit him. Yaeko died on 30 April 1961 at the age of 76 and was buried at a temple in Taitō, further away from Ueno's grave, despite her requests to her family members to be buried with her late partner.

In 1994, Nippon Cultural Broadcasting in Japan was able to lift a recording of Hachikō barking from an old record that had been broken into several pieces. A huge advertising campaign ensued and on Saturday, May 28, 1994, 59 years after his death, millions of radio listeners tuned in to hear Hachikō bark.

A similar statue stands in Hachikō's hometown, in front of Ōdate Station. In 2004, a new statue of Hachikō was erected in front of the Akita Dog Museum in Odate, Japan.

Hachi: A Dog's Tale is a 2009 American drama film that is an adaptation of the 1987 Japanese film Hachikō Monogatari. The original film told the true story of the Akita dog named Hachikō who lived in Japan in the 1920s. This version, which places it in a modern American context, was directed by Lasse Hallström, written by Stephen P. Lindsey and Kaneto Shindo, and produced by Richard Gere. The film stars Gere, Joan Allen, Sarah Roemer, and Cary-Hiroyuki Tagawa.

After the release of the American movie Hachi: A Dog's Tale (2009) filmed in Woonsocket, Rhode Island, the Japanese Consulate in the United States helped the Blackstone Valley Tourism Council and the city of Woonsocket to unveil an identical statue of Hachikō at the Woonsocket Depot Square, which was the location of the "Bedridge" train station featured in the movie.

In March 2011, scientists finally settled the cause of death of Hachikō: the dog had both terminal cancer and a filaria infection. There were also four yakitori skewers in Hachikō's stomach, but the skewers did not damage his stomach nor cause his death.

In 2013, Yaeko's record which indicated that she had wanted to be buried with Ueno was found by Sho Shiozawa, the professor of the University of Tokyo. Shiozawa was also the president of the Japanese Society of Irrigation, Drainage, and Rural Engineering, which manages Ueno's grave at Aoyama Cemetery.

Later on November 10, 2013, which also marked the 90th anniversary of the Birth of Hachikō, Sho Shiozawa and Keita Matsui, a curator of the Shibuya Folk and Literary Shirane Memorial Museum, felt the need that Yaeko to be buried together with Ueno and Hachikō.

On March 9, 2015, the Faculty of Agriculture of the University of Tokyo unveiled a bronze statue depicting Ueno returning to meet Hachikō at the University of Tokyo, Japan to commemorate the 80th anniversary of Hachikō's death. The statue was sculpted by Tsutomu Ueda from Nagoya and depicts a very excited Hachikō jumping up to greet his master at the end of a workday. Ueno is dressed in a hat, suit, and trench coat, with his briefcase placed on the ground. Hachikō wears a studded harness as seen in his last photos.

On 19 May 2016 during the ceremony at the Aoyama Cemetery with both Ueno and Sakano families in present, some of the ashes of Yaeko Sakano were buried with Ueno and Hachikō, her name and the date of her death was inscribed on the side of his tombstone, thus fulfilling the reunion of Hachikō's family.