For three years, Rinko Omuro has worked at Yatsuboshi Confectionery, a company that makes nostalgic penny candy. She loves her job and is proud of her skills, but she often ends up with the less glamorous tasks. When her boss asks her to mentor the new hire, Ryoma Shindou, she is surprised but willing. From the start, Shindou rubs her the wrong way: he is blunt, cold, and insists he does not need her help. Worse, he is right. He learns the work faster, improves processes, and outshines Rinko at every turn. Their professional relationship is tense.

Everything changes after Shindou’s welcome party. He drinks too much, asks to go home with Rinko, and once there, initiates a sexual encounter. To Rinko’s shock, the arrogant junior is devastatingly skilled and attentive, leaving her both satisfied and confused. Shindou then blurts out that he loves her, revealing that his feelings have been building for some time. They begin a secret affair that blends the office and the bedroom. Rinko finds herself caught between wanting to prove herself at work and struggling to keep up with her insatiable, irresistible lover.

As the relationship deepens, Shindou starts to learn social cues he never grasped before, becoming more comfortable with people and opening up emotionally. Rinko, in turn, gains more confidence at work. However, new challenges arise when she is assigned to train another young, handsome new hire, sparking Shindou’s jealousy and testing their bond. The story follows their attempts to balance a stormy office romance with personal growth, moving from a clash of personalities toward something more nuanced.