One Fish, Two Fish, Half Fish, Marine Biologist.

The Small Human.

When Katsuki thought the humans had left that day, because he knew it was late, he decided to swim out of his make shift home. He did that often when he knew no one was around, but this time he messed up because the humans hadn't completely left. There were two still lingering near the tall glass wall. A, what Katsuki assumed, mother and very small human that the blonde couldn't tell if they were a boy, girl, or other. The merboy assumed they were a child. They looked like one, but Katsuki wasn't sure because like Merfolk, Humans came in all different shapes and sizes. It was confusing and that's one of the reasons why he tried to stay away from them.

The mother looked directly at Katsuki then to her child as they spoke to each other and then the smaller human turned around with large eyes. For once Katsuki was curious so he actually, but carefully, swam towards the where they were. They looked nice ,but even if they weren't the blonde knew they couldn't hurt him unless they came in the water. Even though wall was clear it was hard he knew it would be difficult for the humans to break it.

As Katsuki got closer the small human looked excited as they talked. The blonde stopped right at the glass wall observing the smaller who looked at him with big green eyes. They had messy green hair and a yellow box on their back. He was wearing clothes too like the other humans do, but the top part of the clothes had writing on it that Katsuki could read. It was the human language. After he had seen enough he was going to swim away when the human put their hand up to the see through wall.

The blonde frowned as he little human spoke. He seemed so happy and excited, but Katsuki didn't understand why. Though he did put his hand up to the wall right onto the human's since he assumed it was some for of communication like what he does with the tall blonde human. Then the small human had to leave since the woman pulled him away. Katsuki went back to his cave going over what had happened because it made no sense really. He didn't understand what the human was saying by doing that gesture. He couldn't ask the other human either.

Eventually as time went by he forgot about that incident with the strange green humans. Over time he started to understand the language humans spoke and could read their writing too, but that took way longer. Toshinori, as he understood was the tall human's name, was in shock and very happy when Katsuki said his first word. Again. The ash blonde was happy he could understand the humans a little better even if he still didn't like them. He wanted to know what was going on and what they were saying.

The humans that he saw often, besides Toshinori, were very annoying. They weren't mean, or mean to him at least, but they just didn't do things right so Katsuki took it upon himself to tell them. He was used to telling people what to do as a prince and though he's no longer in his kingdom it didn't matter. If they're doing something wrong then the blonde is going to tell them. The humans that worked at the place Katsuki lived didn't seem to care for him much. They didn't talk to the merman like Toshinori did. Well one of them did. She had pink curly hair, but she spent most of her time with Eijirou in or around his habit.

Katsuki assumed the other's just didn't like him. He didn't care that much though. Then a new human one showed up. He had green curly hair and big green eyes. The human also had spots on his cheeks. Katsuki knew him from somewhere, but he couldn't remember that was until the other showed him a picture that his mother took. The blonde vividly remembered then. Izuku was very nice and seemed to really like talking to Katsuki unlike the others.

The more they talked the more Katsuki got to know the human. He told him lots of things and they even swam together. Katsuki missed swimming with his friends. He missed his home but Izuku made him feel a little better and less lonely every time they talked. The human was so strange though. He asked a lot of questions and wrote Katsuki's answers down in a notebook he brought one day. What the blonde cherished the most was when Izuku gave him a picture of the two of them.

One day while they talked Katsuki asked how Izuku got the picture of them when they were younger and Izuku answered but Katsuki had to explain that he didn't know how humans got pictures which was embarrassing because he felt stupid. When Izuku seemed to understand he pull out a rectangle box from his shorts and showed it to Katsuki explaining what it was. Then they took a picture which made Izuku smile even brighter.

A few days later he brought the picture to Katsuki after he made it water proof somehow. The blonde put it by his bed in his cave. He's never had pictures before and it was amazing that a phone as Izuku called it could take a picture of them to keep forever. Human technology was strange, but cool. Katsuki looked forward to the days where he and Izuku would talk even if they had a few mishaps. He was just happy the human liked him though Katsuki noticed something about himself.

He started to feel strange. He started to feel strange towards the human. Katsuki knew what it meant. He understood himself very well but what he was feeling was impossible. Humans and Mermen are not the same. They are not meant to be together. They're just too different. The human living on land and Katsuki living in water being the biggest difference. It just wouldn't work out but even so the blonde wanted Izuku. He likes making the human blush. He likes making him stutter and he wanted to see the human without those stupid clothes on.

Katsuki likes Izuku very much and he wanted him to be his mate. The blonde is old enough and so is Izuku. As time went by it didn't matter that they were a human and a merman. Katsuki just didn't care. Then one day Izuku started asking about how merfolk reproduce and it flustered the blonde. He eventually told Izuku though. He would need to know for when they mate anyway. It's better for the human to have all the information so he doesn't get confused or startled by something.

All in all everything was good between them. It was great even from the merman's perspective. Katsuki felt like they were good friends and maybe it could turn into a romantic relationship. Izuku was even friends with Eijirou. It just was perfect in every way! Izuku was perfect for him. Well that's what Katsuki thought at least until one night when Izuku came to the aquarium and took him from his habitat.