(JJK But there's no curses/Satoru is a merman!)

Mer were a critically endangered species, having been hunted since their discovery nearly three hundred years ago. Satoru Gojo was captured from his home in the artic as a teenager and has spent more then ten years in captivity.

He had a strong build, large with a thick white tail. It was mostly unblemished and practically glowed in the water of his tank. Blue eyes that pierce through the scientists, he was aggressive.

While Satoru was more docile when he was first captured after a few years he had begun attacking any human that came to close to him, rutting himself against the coral in the large tank.

He was almost thirty, in the prime of his life and he was alone. The scientists noticed this, noticed the territorial behavior, the way he seemed to ache for someone to mate.

It was late at night, Satoru having been sleeping in the small cave deep in the tank, strong tail curled towards his chest when a loud splash sounded throughout the tank.

Satoru shot out of the cave, teeth bared in preparation to attack whatever human was stupid enough to invade his territory only to freeze because...

You weren't a human. You were the first of his kind he had seen since he was a child.