i thought i was the real daughter

Selena's whole world is turned upside down when Sienna, the daughter of a maid, suddenly claims that she's the real daughter of Count Estarion. Sienna remembers everything about Selena's childhood, making everyone believe that she's the real daughter. Her once supportive brother and father, who are everything to her, turn cold and kick her out of the house. Even her close friend and fiance turn their backs on her. With nowhere to go, she is saved by the only person who treats with her kindness, Eideun Calypso, a war hero who was once a lowly slave. He asks Selena to be his private tutor and teach him high society etiquette. Why is Eideun being so generous to her? Will Selena be able to find out the truth about her identity? Will she take revenge on those who betrayed her trust?