Ruthainak (Chalida Vijitvongthong) is the smart, resilient, sharp-tongued younger sister.
Her older sister, Nunthaka (Selina Pearce), is beautiful, but spoiled and sheltered.
In financial difficulties, the girls' father asks a member of the Hong Kong mafia, Lin Lang Sur (Tanin Manoonsilp), for a large loan.
When Ruthainak is taken to Hong Kong to confront the furious mafioso, she offers to work to pay off her family's debt.
Later in series, her birth truth is being revealed along with that the real reason behind replacing her with Nunthaka.