Season 1 of Our Century premiered on March 3, 2019.

1914-1939. On the eve of World War I, twins are born to the Winny family: Ania and Mania, Stanisław's daughters. Their mother dies in childbirth. In the difficult times of the war and the interwar period, Stanisław raises them with the help of his mother Bronisława. Both sisters fall in love with the same boy, Paweł.

Season 2 of Our Century premiered on March 15, 2020.

1939-1952. World War II breaks out. Mania and Paweł become parents of twins: Kasia and Basia. Soon, Paweł has to flee the country from the death penalty for insurgent activity. Mania, convinced that her husband is dead, marries Ryszard after many years. Ania leaves Kazimierz and becomes involved with Michał. When the Warsaw Uprising breaks out, Ania gives birth to a son, Michał Junior. She also saves and adopts Ida, whom she names Ewa. Jasiek, unhappily in love with Łucja, is humiliated.

Season 3 of Our Century premiered on March 7, 2021.

1956-1976. The Winny family faces the communist reality. Ania and Mania, now middle-aged women, support their old father Stanisław and his new wife, Andzia. After leaving prison, Michał falls into alcoholism and tries to commit suicide. Thanks to the support of his wife and son, he manages to recover. Ewa and Basia fall in love with Andzia's son, Benito. Kasia becomes a famous actress and gets into an affair with a married lover Adam, with whom she has a daughter, Małgosia. She falls into alcoholism. Ewa secretly marries Benito and learns the truth about her past. Basia starts a family with Tomek. Jasiek falls in love with Lotta and has a son Antek with her, the boy is bullied at school. The marriage is falling apart. Basia and Tomek become parents of the next twins in the Winny family: Ula and Jula.

Season 4 of Our Century premiered on March 6, 2022.

1976-1989. The last years of communism. They are strikes in the country, in which the younger generation of the family participate. Ania and Mania need each other very much after their children started their own separate lifes. It is even more sad for Mania since her husband goes to prison and then leaves for Sweden to protect the family. Kasia struggles co-parenting her daughter with her ex, but soon there is a new man. The marriage of Basia and Tomek is also in crisis, and they are also raising stubborn twins: Ula and Jula. Michał Jr. and Agnieszka have been trying to have a baby for a long time. Karol Wojtyła is elected Pope as John Paul II, and his pilgrimage to Poland brings hope. Ewa returns to Poland with her son Staś, and Jasiek's son Antek also comes back. On the night of the announcement of martial law, the seniors of the Stanisław and Andzia family die.

Season 5 of Our Century premiered on March 5, 2023.