The publicist Claudio and the housewife and choral teacher Helena have been married for many years, but they do not understand and respect the feelings and view point of the partner. Claudio sees Helena as a shopper and "little teacher of a choral" and Helena sees Claudio as an insensitive and rough man. On the night before the fiftieth anniversary of Claudio, Mars, Earth and Jupiter are aligned and Claudio and Helena argue with each other at home and they speak at the same time "If I were you". On the next morning, when they wake-up, they have switched bodies and they have to face the difficulties of the other in the agency, in the school and with their friends and acquaintances.