Gremar John comments

"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 Kobayashi home, the home of Ueno's former gardener, Kuzaboro Kobayashi, where he learned the history of Hachikō's life."

Hirokichi was the

first one who documented the life of Hachi and it was far that he wrote it for

a propaganda. His articles are more convincing than the anonymous source that

you opened. Even if your source is real, the owner of Hachiko's mother was a distant

unreliable witness for Hachi's life and family. Remember that there are people

who introduces different story just to create a noise. And also they might do

it to take revenge for not receiving a limelight in a sensational story.

Maybe the Shibuya station

just reminds Hachi of the activity that his owner had conditioned him. So even

the people around the station mistreated him, he decided to stay that might

caused by his frustration of loss - a similar story in many real dogs out

there.