Behind a beautiful face hides a cruel nature—Baek Ah-jin, who sees through and manipulates others' hearts. After stepping on the sacrifices of many to reach the top, everything begins to change the moment she arrives there. A woman wearing a mask to escape hell and climb to the highest place. And the story of the Xs being brutally crushed by her.

At the brink of his death, the CEO and founder of an IT company's spirit gets stuck inside a smartphone and enlists the help of a young man to do favors on his behalf in exchange for 10 billion won.

Kim Tae Ju is the eldest of three siblings. She is warm-hearted and tolerant, but she also has a hot temper. She cuts off relationships with people whom she doesn’t like. One day, Kim Tae Ju meets Lee Sang Jun again after many years. They attended the same elementary school. Lee Sang Jun is a popular actor. He is sensitive, imaginative, and smart. He is also the eldest sibling in his family. Since he was a child, he has been loved by his family deeply. His family was once in debt, but after Lee Sang Jun became successful, he paid off their debt and continues to support them financially. During filming for an acting project, Lee Sang Jun gets injured and goes to the hospital. There he meets his first love, Kim Tae Ju, whom he knew when he was an elementary school student.

Three female friends, who come from totally different backgrounds, encounter enemies that they want to kill.

A jaded sweets developer meets a cheerful loan company caller while helping his indebted brother. After sharing a meal by chance, they discover new perspectives on life together.

Yong Soo-jeong, an outspoken and popular home shopping host who dreams of becoming a modern-day magnate.