Woo Seo-ri has a rare condition that causes her to change faces every day, making it impossible for her to form lasting relationships or maintain a normal life. One day, she meets Lim Tae-bi, a successful businessman who is immediately drawn to her unique spirit. As they spend more time together, Seo-ri and Tae-bi develop strong feelings for each other, but their love is put to the test by Seo-ri's unpredictable condition.

That night, she makes a decision. She takes Woo-jin (now a seven-year-old) to her apartment. She reads him a bedtime story. She tucks him into her bed—the child’s body small and fragile under the blanket—and she sleeps on the couch.

“I’m Eun-soo,” she says, extending a hand.

Woo-jin, in this borrowed female voice, says: “I’ll tell him.”

: The protagonist, Woo-jin, experiences a supernatural phenomenon where his physical appearance changes every time he sleeps.