Author's Note: I've been posting this on Archive of our Own and I decided I might as well post it here simultaneously. This story originally began as a one-shot, but I decided I liked this AU enough to continue.

FYI, Selkies are creatures from Scottish mythology that can change between a seal form and a human form. They have a sealskin that allows them to turn from human to seal form, and without it they are stuck as a human.

Kirishima was out to sea when all the fish began to swim towards the shore. They passed by him without seeming to notice him at all, some actually bumping into him in their mindless haste.

What could he do but follow?

When he was near enough to shore to see, he stuck his head above the water, peering in the direction the fish were even now still swimming towards. On shore was a boy. The fish were beaching themselves at his feet, the tide silvery and slick with scales.

The boy was starving-thin. His eyes were wild, his cheekbones gaunt, and his clothes were tattered to the point of being no protection at all. He looked out to sea blankly, noticing the fish at his feet no more than they had noticed Kirishima. After a moment the boy crouched down and, pushing fish out of the way, cupped his hands beneath the water, then brought his cupped hands to his lips.

Kirishima swam close enough so he'd be able to touch the bottom, then ducked underwater and transformed into a human, slinging his skin over his shoulder. He came above the water to see the boy tasting the seawater and making a face.

"Why are you doing that?" Kirishima asked him.

The boy looked at him for the first time, surprise barely registering on his face. "I'm thirsty," he said, and Kirishima heard it in his voice, which was little more than a rasp. "I'm so thirsty…"

"Don't drink the seawater!" Kirishima said, climbing out of the sea. He staggered and nearly fell - he could hardly walk, the shallows were so thick with fish. "There's a stream nearby. Let me show you."

The boy followed him. It was only about a half mile, which they passed in wordless silence, broken only by the sound of the waves breaking, the gulls overhead, and the fish splashing. The birds were beginning to notice the fish, some of which were actually beaching themselves, and swooping down to feast as soon as the human was safely out of range.

Kirishima knew that words would be useless until the boy drank, and probably until after he ate too. Kirishima knew the single-mindedness that came hand in hand with that kind of desperation. The boy's world had narrowed to food and water; Kirishima might as well not exist.

When at last they reached the stream, the boy lowered his head and drank straight from it, not even bothering with cupping his hands. The fish, Kirishima noticed, were now trying to swim upstream, against the flow. They were too large for the stream, and there were far too many of them; they were getting stranded on land left and right, and somehow still trying to hop their way towards the boy.

"What are you?" Kirishima asked, when the boy had finally finished drinking.

He got only a blank stare, the boy uncomprehending. "Who are you?" he tried again.

"Bakugou," the boy said, wiping his mouth with the back of one arm.

"Why are they doing this?" Kirishima gestured towards the fish.

Bakugou looked down at them, his eyes widening slightly. He hadn't actually noticed them, Kirishima realized. "I…"

"I've never seen anything like this before in my life," Kirishima said, speaking slowly. He didn't have all that much experience with humans, but he could tell that this one was having a hard time comprehending all this. Whether that was because of his physical state or whether he was actually slow, Kirishima wasn't sure. It called for all the gentleness he could muster. "Did you do something to the fish to make them come to you?" Well, that was obviously a no, judging from the boy's reaction to them. He amended his question: "Do you have any idea why they might be reacting to you like this?"

"No," Bakugou said, staring at the fish, who were still struggling to get to him and dying for all their effort. "I've never been to the ocean before."

"What about lakes? Rivers? Does this happen then?"

"I don't know!" the boy said, the desperation entering his voice again.

"You're hungry," Kirishima said. It wasn't a question. "Let me cook up some of the fish for us, and we can talk after."

The boy nodded, grateful, and they filled their arms with fish.

Bakugou ate like someone starved, licking the juice from his fingers and never taking his eyes off the food. Kirishima did not doubt he would eat anything put in front of him. When he'd finally finished eating - because there were no more cooked fish left - he curled up in the sand near the fire and went to sleep. So much for questions, Kirishima thought.

He went for a swim, but returned quickly after finding himself anxious to make sure the human was still there and still safe. He was, but the fire was dying, so Kirishima piled some driftwood on. Then he curled up near the fire and went to sleep too, his sealskin thrown over him. The cold didn't affect him like it affected humans, but the heavy weight of it made him feel protected.

Kirishima woke up just before dawn to find the human bleary-eyed and shivering, staring longingly at the fire, which had long since burned itself out. Without thinking, Kirishima tossed the skin over the boy's shoulders. He didn't even get a "thank you" in response, although he hadn't really been expecting one.

The sea was quiet. The fish were no longer beaching themselves. There were some dead ones on the shore, but most had been picked clean by birds or washed back into the sea.

"How did you end up at the ocean?" Kirishima asked the boy. He felt a peculiar sort of pride watching him nestle in closer to the skin. It was as if Kirishima's arms were around him, keeping him warm.

"I was a shepherd," Bakugou said. He still stared into the remains of the fire. "I - my village was attacked, so I ran."

He must have run for days and days without stopping, to get here in that state. Ran until he could not run another step. "You're safe now," Kirishima said. "This place is quiet. There are no humans around for miles."

The boy gave him an odd look, and Kirishima realized he'd betrayed himself, so he simply flashed him a grin and leapt to his feet. "I hope you like the taste of fish," he said, making his way down the beach to the shore. "I'm guessing you'll be eating a lot of it." If you stay here, that is, he thought. He hoped the boy would stay. He liked the idea of having a human.

Kirishima realized as soon as his feet touched wet sand that Bakugou still had his skin. He turned to go back but Bakugou had followed him and stood beside him at the shore.

The water began to shimmer and froth as the fish came towards them.

They both watched, open-mouthed and silent, as the fish swam towards Bakugou. It was just like the day before: they swam over each other and leapt out of the water to get at him. Bakugou was more curious now than he'd been last night, and stepped cautiously into the water, wading in up to his knees. The fish swam around him, pressing towards him.

"Don't go in too deep," Kirishima said. "They'll knock you over."

Bakugou gave a sharp laugh of surprise. He reached into the water and, a second later, pulled out a fish. It actually calmed when he held it. Kirishima grabbed for a fish too, but it slipped out of his hands and swam away. When he finally did catch one, it whipped back and forth, struggling to be free and staring at him blankly with one glassy eye.

Kirishima started the fire again. They drank from the stream and ate fish for breakfast, watching the sun rise over the sea. Afterwards, Bakugou wandered the beach, Kirishima's sealskin draped over his shoulders like a cape. Around midday, the boy fell asleep in the sun, and Kirishima stole it back and swam. He collected oysters and seaweed, things he knew humans could eat. Bakugou had given him two huge meals - unwittingly, but still - and the least Kirishima could do was find food for him in return.

But Bakugou wouldn't eat them. "There's enough fish," he said, looking away, when Kirishima offered them to him. "I don't need anything else."

Kirishima threw them back into the sea. He peered into the human's face. He wasn't very good at reading human expressions, but this one seemed to be angry. Whether it was at Kirishima or something else, he couldn't say.

Now the human was staring back at him . "You threw them away?"

"They were for you," Kirishima said. "You told me you didn't want them."

"But… you could eat them."

Kirishima shrugged. "I didn't want them. They were for you." He had no idea why the human was gazing at him like that. Frankly, it unnerved him. He wasn't sure whether he'd done something strange or whether this human just was an odd one. "But if you just want to eat fish, that's fine. I won't bring you anything else."

"Good!"

After spending the afternoon observing him, Kirishima decided the human wasn't actually upset at him. He had to remind himself of everything Bakugou had gone through recently. It could help explain the human's strange emotional reactions. The important thing was keeping the human safe and well-fed, and the second of these, at least, was astonishingly easy.

"How long do you think you'll stay here?" Kirishima asked him that evening. "You can stay as long as you want," he added, so the human wouldn't think he wanted him gone. "I don't mind. Do you think you will stay?"

"You want me to stay," Bakugou said, matter-of-fact.

Kirishima nodded.

"Why?" the human asked.

Kirishima looked him over - his narrow eyes, still suspicious of Kirishima; his shock of white-blonde hair, tangled and dirty; his skin, paler than any Kirishima had seen, already burned from his time bathing in the sun. The firelight painted him gold and orange, and made his eyes seem to glow. Kirishima saw his anger, saw him shoving the gifts away. Saw his fear.

Kirishima didn't say, Why did you answer my question with another question? or Because I want you to know you're safe, or Because I want to protect you or even Because I've always wanted a human.

Kirishima said, "Because I've eaten better in the last day than I have for a long, long time," and Bakugou's smile told him it was the correct answer.

"Yeah," he said. "Me too."

"What was being a shepherd like?" Kirishima asked, changing the subject even though his own question, of whether Bakugou would be staying, had not been answered; they talk about Bakugou's past for the rest of the night - of sheep and farms and the village.

It's only later that Kirishima realized the human had answered his question after all. Bakugou rolls over in his sleep and pulls the sealskin tighter around his body, and Kirishima throws another log onto the fire before settling in next to him on the sand.