Knock knock! A young boy opens his door to find a surprising visitor: a playful polar bear! Boy and bear spend the day together -- dancing, sneaking snacks and hiding from mum -- until, too soon, it's time for the polar bear to return home. But the boy's ordinary day has been transformed by an unexpected new friend who has helped him see the world in an exciting new way. The Polar Bear Day is a striking, wordless picture book with characterful illustrations painted directly onto old cardboard boxes, turning rubbish into something beautiful. Park Jihee's unique artwork will captivate readers while also conveying a gentle message about the importance of caring for our endangered environment.