Fridge / H₂O: Footprints in the Sand

Fridge Logic

• If you play the game, you'll realize that most of the story really doesn't make any sense because Takumi never regained his sight (at first), but some parts of the game continue as if he really can see, like how he knows where Hayami is and how he can know the exact position of his house.
  • Well, that he could do from memory and hearing. But for the Unsettling Gender-Reveal, how did he know?
  • Even ignoring the parts where he may or may not have been able to see, in one scene near the end of the anime, he is pretty clearly blind; yet by stumbling around randomly he manages to find Hinata's grandfather and prevent him from shooting Hayami. How?