four people with different backgrounds, stories, careers and personalities become fast friends. 
each of them has a past they want to hide. 
but as the binding friendship grows, the last starts unraveling itself right in front of them. 

Song Ji Hyo - 31 years old 

She's a hardworking but easy going woman who tries her best to provide the best life for her brother. It always seem like her life is on a treadmill - running nonstop on repeat. In retrospect, it is also something she has to do as a detective. To pass time when she has nothing to do, she loves drinking. It makes all the pain go away and for Ji Hyo - that certain pain is too hard to even continue living at times.

Kim Jong Kook - 36 years old 

He doesn't like to admit failure especially his own failures. Despite his muscular exterior that people admire, he is much more fragile than anybody thinks. The feeling of not being on his best is probably the worst feeling for him. The image that he has worked hard to let people believe - he can't let it crumble down. Especially if that falter will most likely cost his life.

Chen Qiao En - 32 years old 

She tends to become overbearing at times but she only means well. Fear overtakes her. The kind of fear that can cause her to collapse even by just thinking of things that scare her. She's strong willed and determine to make the best out of anything that is thrown at her. To her, image isn't everything. She doesn't care how she looks or even acts in front of people.

Ming Dao - 31 years old 

An arrogant and obnoxious CEO of one of the biggest global internet searching engines. As someone who is practically in charge of making certain celebrities or words trending, it gives him the feeling of power. As if he is untouchable, he doesn't fear of what comes out of his mouth or what he does to people. Past that tough exterior, he finds it hard to let his soft side come out.