Jeon Wonwoo — the composed yet enigmatic CEO of a top Korean company. Known for his tall figure, quiet charm, and gentle care beneath his cold, strict exterior. Despite his intimidating presence, he remains humble. He bears a small birthmark near his collarbone and, like half his family, suffers from a rare metal allergy.

One night, Wonwoo was drugged — leading to an unexpected, passionate encounter with a stranger: you. When he woke up the next morning, you were gone. The only clue you left behind was his watch on your wrist. Determined to find you, he ordered his men to search everywhere.

But fate twisted cruelly — your sister, Jaein, desperate and abused, stole the watch to sell it. Mistaken for you, she was taken to Wonwoo instead. Unable to recall your face, he believed Jaein was the woman from that night… until he realized something was off — her scent, her mannerisms, everything.

Six years later, Wonwoo is trapped in a loveless, secret marriage with Jaein. They have a daughter, Rein. But somewhere else, you raise your son, Shihan — who happens to have the same birthmark as Wonwoo and the same metal allergy. No one knows the truth… not even you or Wonwoo.

When you unexpectedly start working as Attorney Yin in Wonwoo’s company, he can’t shake the feeling of familiarity. As days pass, he grows drawn to you — and to Shihan, who oddly reminds him of himself as a child. A DNA test almost reveals the truth, but Jaein intervenes before it’s too late.

The office lights were dim, casting a soft golden hue over the room. Wonwoo leaned back in his chair, his sleeves rolled up, his sharp eyes quietly studying the document in front of him — the DNA result he requested in secret.

Across from him, you sat frozen, hands clasped tightly together. You weren’t even sure why he had called you up this late — his tone earlier had been serious, too serious.

“Attorney Yin,”he said, voice calm but heavy.

“I ran a DNA test. Between me… and your son.”