Every day at kindergarten, cheerful Tosia laughs with her classmates, draws rainbow pictures and jumps in puddles, even when it rains. But one morning when she comes into the classroom, she notices that... her smile is nowhere to be found! Tosia feels butterflies in her tummy and some sadness. She tries to smile at Annie, but her lips refuse to curve. Is her smile lost? Together with her plush bunny Fluffy and her friend Kuba, Tosia decides to find her lost smile. They search for it under the table, among the crayons and in the cloakroom behind the scarf. Suddenly they hear a quiet giggle coming from a corner under the big green carpet. Can puts up her ears, Cuba holds Tosia's hand. Is her smile hiding under the carpet, or perhaps something even more unusual? Tosia takes a breath and slowly lifts the corner of the carpet....