Workaholic program director Lee Ahn (Choi Soo Young, Girls’ Generation, Squad 38) is in love with her long-time boyfriend Kim Jin Young (Shim Hee Sup, Rebel: Thief of the People). She can’t imagine life without him. And when Kim Jin Young passes away in a car accident, she has to. All Lee Ahn has left of Kim Jin Young is his smartphone. He died trying to say something to her, and the phone holds the key to what it was.

The phone also has a four-digit passcode. Lee Ahn doesn’t know what it is. She only has ten tries to figure out the code, and what he wanted to say to her before he died.

Super nice guy Kim Jin Young (Lee Won Geun, Queen of Mystery) is the latest production director to join Lee Ahn’s team. He doesn’t know why Lee Ahn doesn’t refer to him by name. His somewhat obnoxious niceness also means that the depressed Lee Ahn takes an instant disliking to him. Kim Jin Young still falls for Lee Ahn, and he is determined to win her over.

Between navigating her feelings for the two Kim Jin Youngs, Lee Ahn soon learns that smartphones connect us to the world of social media, but that is very different from actually connecting with the people we know.