"Padiwaradda" means a faithful and loyal wife. To show gratitude to her adoptive father, Rinrapee, or Rin, agrees to disguise herself as his real daughter and marry Saran to keep the promise their fathers made in the past. Saran is a cold-hearted Deputy District Chief who was heartbroken when his lover left him and asks to be relocated to a dangerous province in the South. Knowing that Rin's family has deceived him, he decides to go along with the arrangement to find out who she really is. The more time they spend together, he sees her kindness, not to mention her beauty. Love blossoms slowly, but soon their love is tested when Duangsawad, his ex-lover, returns to him. Feeling guilty about her own secret, Rin has to win Saran's acceptance as his "padiwaradda".