In fact , some research and statistics prove that pets are more sensitive in human’s diseases than we do. Hachi fetched that ball because he knew that his master would die because of his heart disease. It’s his only way to hold him back . Hachi has been waiting in the weeds, waiting for his only fellow to walk him home. His hope has been floating in the breeze, carrying his loneliness and misery all above the ground. Maybe professor knows, but he could never come back.