The series centers around Julius Jr., a young sock monkey with a penchant for invention. Together with his friends, Worry Bear, Sheree, Clancy, and Ping, they build a playhouse out of a simple cardboard box. But when they walk inside, to their surprise and delight, they discover that ordinary objects magically come to life and amazing adventures are just a door away in a magical hall.

At the end of each episode, an original song is featured. The song shows highlights from the shown episode. Most known songs are "Hey Hey Hey", "Come on, Come On", "Honesty (For You and Me)", "Stronger and Braver", "Big Dance Party", and more.

The Hall of Doors leads the cast to:

• Icelaska - A parody of Alaska and Iceland.

• Bugswana - A parody of Botswana

• Seashelly Islands - Named after seashells.

• Twirl-a-World - A parody of Twirl-a-Whirl.

• Castledonia - Named after castles.

• Sagebrush Farm - Named after the sagebrush plants.

• Enginopolis - Named after engines.

• The Invention Dimension - As the name implies, it is where Julius creates all of his various inventions, though in most episodes it is only shown from the outside.

Cast

• Julius Jr. (voiced by E.G. Daily)

• Clancy (voiced by Julie Lemieux)

• Sheree (voiced by Athena Karkanis)

• Worry Bear (voiced by Benjamin Israel)

• Ping (voiced by Stephanie Lynn Robinson)