Shin Nahyeon, who had always dreamed of gaining independence due to her harmonious yet complicated family, finally sees that wish come true when she becomes a millionaire overnight after winning the lottery. Thanks to her newfound freedom and resignation from work, Nahyeon enjoys a life of liberty in her spacious two-story home. When she learns that her childhood friend, Baek Jeon, is returning to the country after having emigrated, she decides to offer him one of her empty rooms. Could that be where it all began? After Jeon, a college student named Dogeon moves in, followed by his stepbrother Yeonwoo — with whom he shares no blood relation — and thus begins the story of these four living under one roof... Welcome to Nahyeon’s reverse harem house, where she just might fulfill her deepest desires!