A married couple visits the wife's family home for the third anniversary memorial service of her father-in-law. Though grateful for the sister-in-law and her husband allowing them to skip formalities and return home, the couple's relationship has recently entered a rut, leaving the atmosphere between them cold. While idling at the in-laws' house, the husband finds his attention drawn to his sister-in-law An's carelessly exposed pink cleavage. Noticing his gaze, An subtly entices him, luring him into a secret encounter that pushes their relationship into uncharted territory.