Shouko Saibara dispenses relationship wisdom as the host of the radio talk show "Cappuccino Break." Privately, she clings to a secret affair with a married man. As her lover retreats under the weight of work and family, Shouko feels increasingly abandoned and resentful.

Her turmoil deepens when an anonymous listener develops an intense fixation. This individual sends unsettling gifts and attempts contact, sparking fear in Shouko alongside a twisted sense of being desired. Her crumbling personal life finally shatters her professional composure, leading to an on-air breakdown where she confesses her own unhappiness and hypocrisy.

During this raw, live confession, the perceived stalker intervenes by rushing to the studio. He offers unexpected support and expresses genuine admiration, helping Shouko see her worth beyond the failing affair. This encounter becomes a pivotal moment, restoring her self-worth and clarity.

The series concludes with Shouko attending a winter festival alongside five other central women. Together, all six witness the diamond dust phenomenon, fulfilling a local myth tied to hope and intertwined fates.