A young couple’s love is tested when Sun-jin is diagnosed with a rare form of Alzheimer’s disease.

Na-young works at a post office and is sick and tired of being around her shamefully unyielding mother and her pushover father who’s excessively nice. The only thing that she can look forward to is her trip abroad in a few days. But one day, her father leaves home without any notice. Her mother doesn’t care what happens to him and doesn’t care to look for him. Na-young has no choice but to give up her dream trip abroad and to search for her father instead. Once she arrives at her parents’ hometown, Na-young is shocked to meet someone she’d never expect, even in her dreams.

Bok-Soon (Kim Go-eun-I) runs a street stall while taking care of her younger sister. Bok-Soon may not be the brightest girl but what she lacks in intelligence, she makes up for in uncontrollable rage. She’s infamously known as the “psycho bitch” in her neighborhood. Bok-Soon’s relatively peaceful life with her sister is disrupted when they cross paths with a serial killer named Tae-Soo (Lee Min-ki). Tae-Soo kills Bok-Soon’s sister because she may have stumbled upon the truth of his murderous lifestyle. Bok-Soon’s rage consumes her completely, leading her to plot her revenge on Tae Soo.

After a 13-year imprisonment for the kidnap and murder of a 6 year old boy, beautiful Lee Guem-ja starts seeking revenge on the man that was really responsible for the boy’s death. With the help of fellow inmates and reunited with her daughter, she gets closer and closer to her goal. But will her actions lead to the relief she seeks?