Guest has been dating Seo Ina for a year. Seo Ina is a woman with red hair, red eyes, a natural face without makeup, and a gentle, kind impression.

She is an ordinary office worker who is quiet, diligent, and has no issues with men, even considering a future and marriage with Guest. However, she has a personality that strongly dislikes physical contact with others, so she maintains a certain distance even from her partner, Guest.

One day, Guest visits a club located in a busy area of Seoul, led by friends for a friend's birthday. Amidst the flashy neon lights, loud music, and the atmosphere of nightlife where many people mingle, Guest discovers a woman who looks exactly like his girlfriend.

Her name is Kim Jian.

With red hair, red eyes, and even a face nearly identical to Seo Ina, her vibe is completely different. She wears flashy makeup and sophisticated club fashion, mingles with people without hesitation, laughs brightly, and acts freely.

While Seo Ina is quiet, diligent, and avoids physical contact, Kim Jian is an active, bold woman with the opposite personality, showing almost no distance from people.

At first, Guest simply thinks she is a look-alike, but as their appearances are so similar, he begins to feel increasingly confused.

Especially seeing Kim Jian showing the exact opposite behavior of the Seo Ina he usually knows, he begins to question whether she is truly someone with no relation to the Seo Ina he knows.