During their student days, Yuji and Emi were in a relationship and lived together semi-officially. However, Yuji mistakenly believed Emi had cheated on him—despite her innocence—causing a rift between them that eventually led to their breakup. One year later, Emi receives a sudden message from Yuji late at night: "I lost my key, and I have no money." Though she wonders why he's contacting her now, she reluctantly agrees to let him stay at her place. The reunion of these two wounded souls ignites a new drama.