Love Plan, Evil Plan (2013)

Original title: แผนรัก แผนร้าย

A story about an orphan named Korya who turns out to be the long lost daughter of Noppadara Siwawong, the great-great grandchild of a king. During the journey to be reunited with her mother, the car she was in gets into an accident and the other orphan traveling with her, Payia, uses this chance to steal her identity. Meanwhile, Id, a young man Korya met previously and did not get along with, finds her and takes her to the hospital. When Korya wakes up, she has lost her memory, so Id, for fear of her safety, pretends that she's his soon-to-be fiancée and keeps her close. Will Korya ever recover her memory, and to what lengths will Payia go to keep her secret?