Thoughtful Mushka and daring Mishka are polar bear cubs who live far up at the North Pole and explore the vast winter world there. When they are out and about, the craziest things happen, including Mushka stumbling over a couple of swan eggs and causing chaos in the bird village, or Mishka befriending the prank-playing baby seal Aura. Soon, however, they are joined by a third: the bear girl Mashka has lost her mother and comes to live with them.