If I may be the first to post as part of the “official” discussion, I’ll go ahead and share some of the observations from the opening scene alone.
They set the tone for Tomoya as a delinquent from the get go, but it also subtly foreshadowed his rough life as well. “The expression on her face… Ah, yes… I remember those days - what it felt like to be naive, simple. That’s something we’ve all experienced.” When I read that, it just screamed some level of trauma to me: he had seen/gone through some shit that had stripped away the innocence, the veil of ignorance that had been over his eyes blinding him from the truth of the world. I know the way I’m saying this is making him seem like he had gone through very dark experiences (like Elfen Lied level dark if you understand my reference), which I actually know better since I went into this having already seen the anime, but it’s something that I picked up on.
Then again, I may be over analyzing Tomoya. Maybe, this was intended to highlight Nagisa’s innocence in contrast to Tomoya’s more serious demeanor.