Eren Jaeger is your normal teenage heart throb. He gets good grades, he has good looks and all the girls are banging down his locker door for a chance to date him. Eren doesn't want the attention. He just wants to be normal.
Prince Levi, ruler of the sea. He's been waiting centuries for his mate. He searched all over except the brighter parts of the ocean. It's forbidden for him. Going upwards puts him in danger of getting caught in a human fishing net. Since he doesn't have a mate means he doesn't have a heir so he was forbidden to go upwards. But, Levi was always a rule breaker, and sometimes, that's a good thing.