Her name was Lee Jangmi, and she was a grim reaper.

His name was Kim Taehyung, and he was a normal human.

She knows his time of death.

Jangmi was always seen as different, an outcast.  She has the ability to see the time at which a person will die.  When she touches them, their eyes tell the story of how they will die, accompanied with their pain, guilt, and remorse.  Normally, she disregards these feelings, but when she meets Kim Taehyung, she has the need to do something about it.