Four misfits find themselves struggling with ordinary problems when they are suddenly pulled through a mysterious portal into the Overworld: a bizarre, cubic wonderland that thrives on imagination. To get back home, they'll have to master this world while embarking on a magical quest with an unexpected, expert crafter, Steve.

Inside of his book, adventurous Harold can make anything come to life simply by drawing it. After he grows up and draws himself off the book's pages and into the physical world, Harold finds he has a lot to learn about real life.

After discovering she can see everyone's imaginary friends, a girl embarks on a magical adventure to reconnect forgotten imaginary friends with their kids.