Since the beginning Man has always had names.
Not the normal names that parents give to their newborns, but the names of their soulmates.
It appears when you are born, meaning that your soulmate is older than you. Or a few years later, and your soulmate is younger than you.
This is the tale of two of those soulmates and how...well...let's just day that they had a very exciting journey ahead of them.