"To me, he's my destiny. To him, I'm just a girl he knows."

A young woman grieves the unexpected death of her neighbor and former high school classmate, as she liked him ever since she met him. She had never gathered the courage to confess, and she wasted whatever little chance she had with him.

During a drunken bus ride with a man she's been meeting from time to time, himself a former schoolmate, the bus gets into an accident, and both her and the man find themselves transported 10 years in the past.

Together they agree not to tamper with the past because he staunchly refuses to change his already idyllic future, but she progressively starts seeing this as a second chance to save the life of the boy she loves.