Ryuutaro remained positioned in the door frame while the others walked into the room, feeling a bit like a ghost. For once it wasn't so bad though.
Sure, it was an awkward feeling, but it was an appreciated insight in what kind of daily life Hayato had come from. It had always been so much trouble to imagine, with places and people he did not know and could not imagine up either.

This made it easier.

Ryuutaro found himself thinking back to their time in his world. Hayato had probably had a similar ghost-like feeling at the get-togethers. Even if they belonged with each other, they really didn't belong into each other's worlds. Not until now, at least.
Ryuutaro had thankfully stopped really identifying the dimension he came from as his world... it made it at least a tiny bit easier to think about settling here.
He wondered if he would be expected to go to this school as well. An odd thought. But then again, this world did not have records about him, so how would they know? Truth was... Ryuutaro just had no clue how a school system worked.

So he just watched the others, smiling vacantly to himself.