Vincent is staying with his aunt Mimi for the summer while his mom recuperates from surgery. Mimi's drab city neighborhood, complete with an empty dirt lot across the street, doesn't seem too promising. But then Vincent meets Toma, a boy who lives nearby, and things start looking up. Mimi has a mysterious box of "dirt balls" in her apartment. When she asks Vincent to get rid of them, the fun Vincent and Toma have throwing them into the lot becomes the start of a budding friendship. Then one day, they notice new shoots sprouting all over the lot. Maybe those balls weren't just made of dirt after all!