Mischief City.

Mischief City is a Canadian animated children's show based on the book of the same name by Tim Wynne-Jones. It follows the adventures of 8 year old Winchell Adams in the extraordinary world of Mischief City. While in this fantasy world, Winchell is accompanied by Maxine, another 8 year old, and her two monsters Hey Hey and Mr. Cube. The group often faces odd and unusual problems most of which are a direct result of Maxine's troublesome older brother Duane. The series first aired on January 1, 2005.