The series is about an incident that takes place when the owners of the boarding house called 'Guest Summer Palace', which breaks stereotypes, and boarders with secrets gather to find Lee Seol who disappeared 13 years ago.

Missing ?70 billion appears to three sisters who grew up in absolute poverty but with a close bond. Entangled in a conspiracy that involves the rich and powerful, three sisters who wanted to live like everyone else confront a life task whether to keep or to return the money.

Set in the 18th century, the drama depicts the love story between King Jeongjo and royal concubine Seong Uibin.