You have blanket permission for Hiro to do what you gotta do. He's usually pretty open with how he's feeling. But he'll sometimes plays up the joker act to make sure that no one knows what's bothering him and hides more sad and somber feelings underneath.

And he'll also say or do weird/funny business to avert uncomfortable topics, try to keep people happy or attempt to control the flow of a conversation. Otherwise, he's still a very quirky and optimistic person.