If the 'hachi original story' is about Hachi's journey, then apart from Hachi himself, there might be some friends or family members as main characters. For example, a wise old mentor who guides Hachi, or a loyal friend who stands by him through thick and thin. There could also be an antagonist, someone who opposes Hachi's goals or tries to cause trouble for him.
Definitely. The story of Hachi originated from a true event. It showcases the remarkable devotion and unwavering love a dog can have for its human companion.