A prophecy from the holy goddess tells, that people with red hair will bring the end of the world. And so all newborns with red hair are killed.
But then the time comes, when destiny or maybe coincidence brings two redhaired people together, who survived in very different ways.
And suddenly they decide to change their way. They won't just survive, they would bringt light in the dark prophecy about the end of the world. And their part in it.