Continuity mistake: In the opening scene the grandson writes Hachiko's name on the blackboard. After a shot of the classroom, we return to the blackboard ("Everyone calls Hachi a mystery dog.") and Hachiko's name has moved on the blackboard. Notice the position of the letter "C" and the bottom of the letter "I". In the final classroom scene Hachiko's name has moved again. (00:00:55 - 01:27:35)
Continuity mistake: At home, the first day Hachi fetches the ball, he is either standing on the sun or on the shade, depending on the shot.
Continuity mistake: The leaves around the skunk appear, disappear and change position between shots.
Continuity mistake: The day Hachiko is onstage during rehearsals, he sniffs a dancer's foot, yet a frame later they're five meters away from each other.
Continuity mistake: When Ken reads about Hachi on the newspaper it is visible: " Hachiko looks for professor seven years after he died of a heart attack", but in the next scene with the dog in front of him the subtitles show: "It's been a year, hasn't it?" when he speaks in Japanese.
Continuity mistake: When Hachiko goes up to the bedroom, the position of Parker's shoes differs between the dog's point of view and the rest of the shots.
Continuity mistake: Hachiko changes between male and female from puppy to adult age in various scenes.
