Sota Yukimura (Hokuto Matsumura) works in the General Affairs Department of "Nose Cosmetics." He is an unassuming, harmless man who keeps a low profile—the type who blends into the background. Shy and lacking presence since childhood, he has led an ordinary life with nothing to boast about. That is, except for one thing: he has harbored an unrequited love for his first crush for twenty-five years. In stark contrast to Sota, Mariko Nose (Sae Okazaki)—the daughter of the company president and head of the Second Brand Division—has lived a dazzling, charmed life. She spearheaded the cosmetics brand "Velel," turning it into a massive success. While many employees view her with a cynical eye, dismissing her achievements as mere nepotism, she shares a close, candid bond with only one person: her secretary and single mother, Izumi Takeda (Nozomi Sasaki). For a rank-and-file employee like Sota, Mariko—an executive of the same age—is someone far out of his league. He has never even spoken to her, and she is completely unaware of his existence; yet, when he tries to help her out of a bind at a café, she responds with a distant, cold attitude. However, the two had actually met once before, triggered by an incident during their childhood... For the twenty-five years since, Sota has quietly watched over Mariko's life. He had always been content simply observing her from afar—or so he thought. Mariko, aiming to launch a new skincare line for "Velel," is told by her father—company president Ginjiro Nose (Ken Ishiguro)—that she needs to rework her proposal. Seeing her in distress, Sota breaks his silence for the first time and speaks to her. From that day on, Sota's pure love begins to spiral into madness. Meanwhile, mysterious incidents start occurring around Mariko. Her ordinary daily life is turned upside down as events take a thrilling, dangerous turn.