In a girls high school classroom, a father, Seo Kyung Do, speaks to the class. He entertains the class and earns their praise. However, a student, Lee Sun Woo, watches anxiously. She looks nervous and uneasy. The class was going well, but because of Kyung Do s mistake, everything goes downhill and his true identity is revealed. He was hired by Sun Woo to play her dad at her class Parents Day because she had lost contact with her father after her parents divorce. Tension forms between these two over $200. Sun Woo lives with other runaway teens, calling themselves a fam, sharing each other s pain and living as a family. Because cash is precious, she can t forget the $200 she couldn t get back from Kyung Do. She uses a fake I.D. that a fam member made her, to get a job as a fill-in singer at a live cafe. And thus, her revenge on Kyung Do begins. Kyung Do offers Sun Woo a job more befitting her age, and she asks for a teenage girl s room that anyone would envy. The two switch places as employer-employee and cease fighting for the time being. Thereafter, Sun Woo advises Kyung Do on what s popular with teenage girls. As they grow closer, Sun Woo finds out that Kyung Do s daughter is.