The first time Yamato rides the train to his mother's apartment, he gets off at the Shibuya train station because he doesn't feel like seeing anyone. This act of rebellion is either driven by resentment for having to travel to spend time with his own brother, or by pure absentmindedness after thinking such angry thoughts. On a whim, he decides to spend hours at the arcade and then head home to kill time before his mother phones his father and the truth eventually pours out.
But then he comes across the statue of Hachiko upon leaving the train station. It's the akita dog who had waited at that very same station for his owner to return from work so they could walk home together. But there was no way for the dog to know that his human had died at the university where he worked as a professor, so the akita dog returned to the station every day for ten years, hoping to hear his friend's familiar footsteps, until death took him as well.
Shame immediately paralyzes Yamato, disappointed in my own behavior. Goosebumps pop up and down his arms at seeing Hachiko still waiting even after death for someone who would never return. Somehow, Hachiko's bronze statue inspires the resentment smothering Yamato to lessen. He imagines that the dog might have sensed that his friend had crossed some bridge that couldn't be retraced, but that the akita dog had faith, anyway. Maybe it wouldn't hurt Yamato to have some too, especially when others – like his mother, whose hugs hopefully still feel the same – were waiting for him faithfully.
Yamato boards the next train, determined to visit the other half of his family.