Gong Woo-Jin is a 30-year-old single man and he works as a set designer. Due to a trauma he experienced 13 years ago, he does not want to have a relationship with others. When Woo Seo-Ri was 17, she fell into a coma. 13 years later, she wakes up from her coma. Her mental age is still that of a 17-year-old, but she is now 30-years-old. Gong Woo-Jin and Woo Seo-Ri get involved with each other and fall in love.