Mary Wi is a wanna-be eco-friendly designer, but she did not major in design, is not qualified and has no social connection in that field. She is cute looking, just like her late mother, but she is short-tempered like her dad. Mary's dad believes that there's no man who is trustworthy and he insists that he will pick Mr. Right for his daughter. Though they always quarrel, Mary is daddy's little girl and thinks her father is the best.
One day, Mary goes to a glam rock concert and there, sees a pretty looking but rough rocker, Mu-gyul who sings like there’s no tomorrow. As they get to know each other, they notice each other's personal charms and fall in love rapidly as if they have known each other for years. On the other hand, Mary's dad, since she was 5 year old, has already arranged Mary's marriage with Jung-in, son of his rich friend, Jung-suk, who has supported him financially. Mary, not knowing this, and being passionately in love, ties the knot with Mu-gyul. Jung-in, then, enters the picture. Mary will live in a pent house in the Chung-dam area with Jung-in, a rich president of an entertainment agency, while she lives with Mu-gyul, a poor indie-band rocker in an underground apartment in Hong-dae district, at the same time. After 100 days of polyandrous marriage, she will have to choose which one is Mr. Right. She goes through an inner conflict over two different men with different charms.