Return to the Nest tells the story of a young woman who, following the death of her mother, sets out to find her father, whom she has never met. In 1985, during the Iran-Iraq War, a large-scale operation is carried out to bring 215 passengers from Iran to Turkey. Among these passengers, whose lives have been saved, is a young Japanese girl named Keiko. Keiko falls deeply in love with Zafer, a lieutenant in the special forces stationed at the Turkish Embassy in Iran. However, the war forces them apart. Zafer manages to get her onto the plane heading to Turkey to save her life. But there is one crucial thing he does not know: Keiko is pregnant. After arriving in Turkey, Keiko gives birth to her daughter Yumi.