[ No explanations before hugs. That's the rule. Hiro rushes over to his brother and throws his arms around him, hugging tightly like he's scared to let him go. Because he is scared to let him go, now that he's here and apparently not a ghost or a mirage or - oh god. He's going to start hyperventilating if he lets his mind run away with him like this. ]

What? What do you mean? How are you here?

[ Because he sincerely doubts his brother found a hole the way Hiro did. ]