"So...what year is that?" No one's bothered to mention what grade he's in so far. He knows it means Yu's probably a year younger, but that doesn't help much if he doesn't know what year he's in for reference.

But then his eyes go wide as the rest of it sinks in. It doesn't actually make him remember Yu, but he knows he was found and brought to the hospital, so he's glad to meet him.

"Oh! You're the one who found me?" he asks. "Thanks for that, I suppose! Uh...do you know why I was out in the woods though?"

And he looks at Yu as though he fully expects him to have some sort of answer. He's the one who found him so he must know something about why he was out there - right?