Cho Yeo Hwa has been a widow for 15 years. Her in-laws are the most prestigious noble family in the kingdom. During the day, she leads the life of a widow devoted entirely to her dead husband's memory and rarely ventures outside the gate of her home. At night, Yeo Hwa dons the mask of Hero, who secretly jumps over the surrounding wall to save the helpless.

In Seoul, a suicidal student meets a young woman who decides to join him in his fatal gesture. Dongsoo, an unsuccessful filmmaker, spots a beautiful young woman, who happens to be the lead actress in the film he has just seen. Their stories will cross paths thanks to their love for cinema.

Ji-hae's friend is having problems expressing her feelings to the boy she loves, so she asks Ji-hae to write e-mails to him in her name. As the boy falls in love with her letters, Ji-hae discovers the story of her mother's romance which is remarkably similar to her own circumstances.

Woo Ah-Jin lives a luxurious life due to her wealthy father-in-law, but her father-in-law's finances become decimated and her husband betrays her. Woo Ah-Jin's life hits rock bottom. Park Bok-Ja is a mysterious woman and she hides her heartbreaking story. She brings about fierce hardship on Woo Ah-Jin.

At a difficult place in his marriage and career, a middle-aged man gets a shot at a do-over when he's transformed back into his 18-year-old body.

Three siblings, exhausted by the monotony of day-to-day adulthood, seek to find fulfillment and freedom from their unremarkable lives.