Lison dreams of the day when she will be able to wear her older sister's red coat: a real grown-up coat! And when this long-awaited day arrives, in the middle of winter, Lison boasts: it is beautiful, it is warm, it is perfect! The next morning, while leaving for school, Lison meets a little girl begging with her mother, shivering in the freezing cold of January... Lison hesitates: how to help this little girl who is the same age as her? What if she gave him her coat to keep him at least a little warmer?