Sara, for the first few episodes, is invisible. She only lets her presence be known when she wants it to, by holding a pillow, a paper crane, etc. In step five, she gains the ability to be visible, but still goes invisible occasionally when it suits her. Sara is probably the most rational member of the family, often being the most reasonable one in a situation. Nevertheless, when Mikael moves in across the street from the family's house, Sara gets a ridiculous crush on him.