A drifter lives in people's houses while they are away and repays them by doing chores for them. His life changes when he meets a beautiful woman who wants to escape her unhappy marriage.

There are a lot of dark secrets at Seonam Girls High School, but nothing is too difficult to solve for the school's Sherlockian group of private investigators. Mentored by their teacher Ha Yeon Joon, these beautiful and intelligent sleuths use investigatory finesse to solve hot-button cases, including abortion, bullying and suicide.