Eiko is the daughter of a distinguished family of dentists. For the sake of her household, she enters an arranged marriage with Shuichi, an excellent dentist. She is prepared for a loveless marriage focused solely on producing an heir and expects to proceed with a pragmatic, emotionless attempt at conception right away. To her confusion, Shuichi refuses to go through with it. Instead of the cold transaction she anticipated, he begins to slowly and meticulously arouse her, focusing on one part of her body at a time. Though Eiko tries to maintain her resolve, his careful, drawn-out touches leave her mind and body at odds, and she finds herself increasingly overwhelmed by physical pleasure. As she begins to suspect that Shuichi might actually have feelings for her, her own heart starts to waver. However, she overhears a comment that makes her believe he is only interested in acquiring her family's hospital. Their emotions grow misaligned as their intimate encounters continue, with Eiko struggling to reconcile her growing desire with her fear that she is not truly loved. The story follows their journey from a practical arrangement to a genuine emotional and physical connection, revealing Shuichi's long-hidden childhood affection for Eiko and the reasons behind his reluctance to complete their union. This side story serves as a prequel that explores the courtship of the parents of the male lead from the main series.