I'm really freaking confused at the end. He cried because she died and felt guilty or because he fell for her…
I think guilt. The title - Innocent thing could give us a clue. He turned a crush into something more for her. he played out her fantasy so she continued to live in it. At the end I think he felt bad and remorseful because she started off innocent. Him thinking back at her playing in the chalk dust at the end.
of course this is only my interpretation/opinion of it.
of course this is only my interpretation/opinion of it.