After quitting her job, Yu Mi became a star writer at the peak of her fame, with her "Writer Cell" taking charge over "Love Cell." But the sweetness of success doesn’t last forever. Her days soon turn dull and monotonous until a man named Sun Rok steps into her life. Facing this younger man, Yu Mi discovers a new kind of love — unexpected, disarming, and deeply stirring. Once a common to-go girl in her 30s, Kim Yu Mi is now a celebrated romance novelist. But with no more new goals or challenges, her cells have fallen asleep, leaving her days lifeless—until Sun Rok appears. Yu Mi learns that even a star romance writer can be a total rookie when it comes to real love. Sin Sun Rok, an editor in his 20s at Julie Publishing, is all about facts, logic, and boundaries, feeling perfectly relaxed when staying home alone. But as Yu Mi starts to invade his world, he draws a line—only to find himself slowly, irresistibly, falling for her.