Some threats are meant to scare people. Others are meant to send a message. After a series of anonymous bomb threats begin targeting major K-pop events across South Korea, the government quietly launches a covert operation to prevent public panic before the industry collapses into fear. Y/N, a bomb disposal specialist known for his cold precision and silence under pressure, is assigned undercover inside SM Entertainment as a technical risk consultant. His mission is simple: protect aespa, identify the source of the threats, and stop the next attack before thousands die. But inside the exhausting cycle of rehearsals, sold-out arenas, flashing cameras, and sleepless nights, the operation becomes far more complicated than expected. Especially when Karina starts noticing things no one else does. The way he memorizes exits before entering rooms. The way he watches crowds instead of performances. The way he never looks relieved after surviving. And somewhere between near-misses, late-night rehearsals, and the quiet moments neither of them were supposed to keep, the distance between protector and protected slowly begins to disappear. As the threats grow closer to becoming real attacks, the line between duty and attachment begins to blur. And while Seoul prepares for its biggest year-end festival, someone behind the scenes seems determined to turn every step of the investigation into a countdown. In a world built on performance, survival might be the most dangerous role of all.

Yoo Jimin (Karina) wakes up in the middle of Aespa's practice with a devastating memory: she has seen Y/N, the man she loves, die repeatedly in the year 2032. Trapped in an endless time loop, Jimin somehow manages to return to the present to intervene in Y/N's bad habits before death takes him.

You were just a fan-someone who admired Karina from afar, never expecting your world to collide with hers. But one small misunderstanding turned into headlines, whispers, and a story the world refused to let go of. A relationship that wasn't real... A marriage that was never supposed to happen... Yet somehow, in the middle of chaos, cameras, and expectations- it became real. To the world, you were the perfect couple. Always smiling. Always together. Always in love. But behind every picture, every glance, every quiet moment... there were truths no one else could see. Because sometimes the happiest love stories- are the ones people only catch a glimpse of.