Set in Rio de Janeiro's beginning of the 20th century, Lado a Lado tells the story of a friendship between two women:Isabel, descendent of a poor slave, and Laura, a white girl, daughter of a baroness. Despite their very different origins and backgrounds, the two girls become very close while aspiring to a future of equality between men and women, and between black and white people. They meet on their wedding day and build a friendship capable of shaking the tree of Constância, Laura's mother, a baroness who refuses to accept the innovations of the twentieth century and the change of the country into a republic.