Cha Hong Do has social phobia and blushes uncontrollably around others. Curious and intelligent, she learns about the world through books and the internet. After the death of her grandmother—her only link to the outside world—Hong Do begins working as a maid, hiding her identity by disguising herself as an elderly woman.

One day, an unexpected encounter leads her to cross paths with Ko Yi Seok, a psychiatrist who may just change her life.