...Well, you guess there's one thing you can do to break the awkward silence. Actually talk to Shinjiro-san.
Sort of, anyway. Thinking a bit harder on it, you don't actually have a lot you can talk with him about. Things like the Dark Hour and Personas aren't really good for casual conversation. So you can't really have that.
Well, at least you've got manners to fall back on. If you use those, you can maybe make him like you a bit more! Being polite to people is how you make them like you, right?
It's as good a start as anything else, you suppose. "Hey, Shinjiro-san?" You start, hoping that your voice doesn't betray your nerves because you have no idea what you're doing.
"What is it?"
"Well, I guess I just... I wanted to say thank you. For walking me back like this. And, well, for being so nice to me in general." He didn't have to do any of this. Most of it, you'd never even considered asking for. But he did so anyway.
Yeah... that's Shinjiro-san for you.
It takes a few moments for him to respond. "...You don't have to thank me. I don't-" He cuts himself off.
...Of course you deserve it. Stop trying to hurt yourself like this.
"You don't what?"
"...Never mind. It doesn't matter." It's already dark, but even if it weren't, you don't think you'd be able to figure out what he was going to say just by looking at him. Not that you've ever been the best at reading people, but... all you know is that he's upset about something. And that's not good.
"Is something wrong?" You ask him. He's not looking at you again. You need to find a way to permanently fix that, really.
"Of course not." He's lying. That much you can tell without having to think about it much. "I just- you shouldn't be thanking me for this, I'm not-" He stops again. "...Look, isn't that your dorm?"
So it is. You don't really feel comfortable leaving him like this, though.
[ ] Listen to him and go back without question.
[ ] Thank him again before you go. (+Diligence)
[ ] Try to get him to admit what's wrong. (+Empathy)
[ ] "Shinjiro-san... you know you don't owe me anything, right?" (+Courage)