Katsuki was going on walk by the beach, just grumbling 'bout random shit (cuz he's a grumpy mf), until he got distracted and fell into the water. He tried to swim back to the surface, but he was already too deep in the water. As he felt like he was gonna pass out, an unfamiliar figure swimming towards him.. They had a fish tail..?

Katsuki: in his head W-what the..?!