It's hard to compare Torigaya because he usually stands at an awkward angle, but at 5:43, when he is shown with Wa-san, he's actually below Wa-san's shoulder length, which leads me to suspect that he's already a small character to begin with. Also, at 21:23, Torigaya is shown to be almost the same height as Chihaya, but that doesn't tell us much, or does it?

You just might be overanalyzing, but it's hard to rub my eyes off the truth that he does transition into a fox-like face in the opening. However, not enough evidence is shown, so I do not believe that he's part of the Saginomiya plans (until further proven by latter episodes).

Quote Originally Posted by enkoujin
Finally, if Washizu has no friends due to his infamous delinquency, how and why is Torigaya reaching out to Washizu as a friend in the first place?
During a flashback in episode 8, Torigaya admired Wa-san's strength, so he was the first person that ever approached Wa-san calmly and... Wa-san had a friend. His first friend.