In 1997, a mysterious ghost saved humankind and then disappeared. The mysterious ghost appears again 24 years later and helps a serial killer escape. Kim Sae Ha, Jung Sae Byeok and Song Eo Jin pursue the ghost for different reasons.

如果说<Heart Signal>描绘了青春男女间痒痒的恋爱初期样子，那么<Heart Pairing>则将焦点放在了适婚年龄事业有成的出演者们考虑价值观、经济观和恋爱观寻找未来配偶的样子上。
约1个月的拍摄先在意大利托斯卡纳5天再返回首尔相处20天。
朴PD“因为出现了梦想结婚的出演者，所以计划讲述更真挚、更深刻的恋爱故事”

A troublemaking veteran detective and a rich rookie detective go on a work trip to Seoul to reinvestigate a mysterious murder.