"Have you ever thought about who you were in your past life? Well, I remember who I was. I remember who killed me." In the last moments of her death, Nina saw who killed her and the man she loved. Given a second chance, this time will she be able to save him? Will she be able to save herself? By Chance follows the story of Nina, through her remembering of her past life and her meeting with people from her past at the present time.