"When we were young, our parents had explained that we were to complete an important mission. There wasn't enough love on the planet. People had lost faith in happily ever after and stopped believing in romance. All twelve of us had agreed to be born on Earth to show the world that true love exists."
So many thing wrong with this.
1. If you agreed to be born for this, why did your parents have to explain it to you?
2. If your mission is to prove true love exists, why are you having to hunt for your other half? Why wouldn't they be placed with you?
3. How exactly would these twelve people pairing off help bring love back into the world? Especially since they are all clustered in London.