Seo-hyun is an ordinary housewife in her late thirties with a ten-year-old son and a successful architect husband.

For Seo-hyun, life is a series of banal routines, but she is well provided with upper class comforts.

Her sheltered life is suddenly threatened with the appearance of U-in, her much younger sister's attractive new fiancé.

U-in approaches Seo-hyun and attraction evolves into a passionate affair.

Seo-hyun is aware that falling for the younger man will destroy her and her family, but she cannot help herself and the new feelings that are stirring within...