Soulmates (Sengen)

In this AU when people turn 18 they get there soulmate. Wondering how they know? One their birthday hits, on their wrist a symbol will appear the persons soulmate will get the same symbol. They can communicate if they write something under their symbol whatever they wrote will appear on their soulmates wrist. Though when the green light flooded the earth, the soulmate era was put to a halt, and everyone was forced to rebuild humanity with much loss of time for love. That's it enjoy the story