Be careful what you wish for
Giovanni lives in New York City with his mother, who is an opera singer. His father was a set designer, and the one thing "Van" has kept through all of their moves to different cities is the maquette his father had- a small stage with curtains. He finds objects out on the street and uses them to reinact scenes on the stage. His frequent moves, as well as the fact that he is hard of hearing, occasionally makes it difficult for him to make friends, so when he runs into Pebble in the park, he feels a connection to her. She's a bit odd, wearing a long coat in the warm weather, but he follows her and eventually finds out that she is part of a group of Collectors who gather wishes and keeps them safe in an underground facility. He also meets Mr. Falborg, who collects a number of different things, including Wish Eaters. He claims that Pebble's group is trying to starve and abuse the Wish Eaters, who are little, tiny and cute, and he gives Van a Wish Eater of his own to keep. Since he needs to feed it wishes, he wishes for a number of things in order to feed it, but wishes are unpredictable. For example, his mother is dating the father of Peter Grey, who doesn't like Van very much, so he wishes that the two parents won't be together, and his mother gets a job at La Scala in Italy. When he then wishes to stay in New York, something happens to his mother to prevent her from traveling. The Collectors are after Van, and when they finally corral him, he finds out more information about what is going on, and decides which side he needs to be on.
The story with Peter adds a nice dimension, since children whose parents are dating each other probably are very ambivalent about each other. Van's hearing loss is well portrayed, and his struggles with understanding speech are explained in a way that will help younger readers understand what it might be like. Having an opera singer as a mother is not something many children have, so that was interesting as well.
Readers who enjoy books where the good and evil sides aren't particularly clear cut, like Colfer's Artemis Fowl series of Delaney's The Last Apprentice will enjoy Van' confusion over whether he should believe Mr. Falbourg's take on the Wish Eaters or Pebble's and the Collector's. I'm still a little torn myself, since Mr. Folbourg is introduced as a kindly, crinkly-eyed older gentleman but at the end manages to disappear, much to Van's dismay. This could be a stand alone title, but I can see the series continuing as well.