A Day of Sun and Rain is a heartwarming family movie that follows the story of a teenager as he navigates the complexities of love and grapples with the pain of loss. Through moments of joy and sorrow, he learns important lessons about life and the power of family.

At sixteen, Maria becomes an underground revolutionary. In the terrible year of 1919, while conducting propaganda among the sailors of the interventionist fleet, the heroine meets the Spanish sailor Pablo. After parting, they meet again only a few years later. Pablo and Maria leave for Spain for illegal work. After burying her husband and son, she trains personnel for Soviet intelligence during the Second World War.