The Siblings (1966)

Kostas returns to his homeland after many years abroad and searches for his three children who were lost during the Occupation after his wife's death. In the meantime, Manolis, a poor young man in love with a girl called Kaiti, becomes a successful popular singer thanks to the unreserved help of his friend, Sonia. Sonia is also a singer and in love with a rich young man, Stelios, whose mother doesn't want her as her daughter-in-law. Manolis and Sonia are brother and sister, but they only find out when it is too late, after they locate their father and their other brother Sokratis.