Eun Bang Wool falls in love with Park Woo Hyuk who received a heart transplant from her ex-boyfriend.

Still recovering from a heart transplant, a retired FBI profiler returns to service when his own blood analysis offers clues to the identity of a serial killer.

After losing her fiancé in an accident, Saeko feels an inexplicable connection to a stranger — who, by a twist of fate, received his heart and memories.