En las buenas y en las malas presents the story of Valeria and Sebastian, a couple who have been together for several years and, after pressure from friends, family and colleagues, have decided to commit and put a date to the wedding. Although they love each other deeply, both avoided the commitment in silence, trying not to bring the issue to light and evade it if possible. But the years had led to the relationship at that moment and both, almost by inertia, decided to accept it. While the people around her are excited and happy, Valeria and Sebastian are secretly scared, increasingly unsure of the commitment and accidentally try to boycott each other. The closeness of the wedding date makes her insecurities manifest and the real problems begin, especially for Sebastian, who, fearful of losing his freedom and identity, will face the temptation of another woman to leave his beloved Valeria.