Izuku was starting to feel that familiar ache in his arms after ten minutes of rowing. Sweat and sea-spray coated him in a fine layer, saltiness on his tongue as he chewed on his lower lip. A pink dusting across the sky accompanied the early-morning sun. The shore shrank further and further into the distance as he continued, seagulls and clouds his only company above the surface of the water.
He still kept an eye out for anything lurking underneath. Once, he thought he saw something, someone—a form with what looked like coral-red hair and stone-grey skin from under the water, but before Izuku could make out any more, the creature had already disappeared from sight.
It wasn't like Izuku knew what he wanted from him, after all this time, anyway.
He came to a stop and pulled one of his oars out of the sea. After wrapping his handline around his arm, he tossed a flax net, watching it to ensure it sank well with the weights attached around its circumference. He waited for a few minutes. Then, he heaved the net back up, the muscles in his arms and back straining as he brought more and more of the handline out. It felt like a decent haul from the heft of it. Fish appeared as the now teardrop-shaped net rose, flapping and flailing in a frenzy.
Once he had wrangled all of them into the rowboat, he worked on separating out the fish into his wooden buckets. Sweetfish, dace and a few tuna as big as his forearm indicated the Midoriyas would be popular at the market today. Thank goodness. His dexterity had gotten a lot better, he thought, fondly remembering how many slipped and wriggled their way out of his grasp when he was just starting out. He tossed out some of the immature fish, giving them a chance to grow. After he finished, he was pleased to see the buckets were already a third full. He would only need to do a couple more sweeps before he could head back and help his mum pack up.
He was about to throw the net again when his boat started rocking, the calm waters now swelling and undulating. Huh. Was a storm coming in? Izuku swivelled his head around, but the sky looked clear in all directions.
A bump appeared above the surface about twenty metres ahead. It looked like it could be a cetacean. Then, another one, right in front of it. A pod of dolphins?
Yet another breached, except… It kept rising. And rising. A black, towering form shucked off the waterfalls gushing around it; a reptilian head with glowing white eyes atop an ever-growing serpentine body let out an unholy screech that rocked Izuku to his core.
Izuku couldn't breathe. His body reacted before his mind could process what he was seeing, rowing away from the monster harder than he had ever rowed in his life. The smacks of the oars rang out with each pull and the creature turned its head towards the sound.
The sea serpent was huge, big enough from its head to its thrashing tail to wrap around Izuku's little rowboat four times over. It surged towards him and Izuku sobbed as tears cascaded from his eyes. Burning muscles and adrenaline couldn't distract him from the fact that he was going to die. His mother would never even know how, only that he went out to fish one day without ever returning.
The monster was catching up to him fast in spite of the head-start Izuku had gotten. Within a few more moments, it would be on him. Izuku's rowing intensified, his body still trying to keep him alive when his mind already knew it was hopeless.
Just as it got so close that Izuku could practically see its individual scales, a massive explosion of light and heat burst out of the sea and caught the serpent directly on the head. It screamed and flailed, then turned its attention onto its attacker. The churning waves almost knocked Izuku out of his boat, but he grabbed onto its side and held on for dear life.
More blasts rung out. These ones were smaller, spreading the area of effect over the monster's whole body in quickfire succession. Liquid sputtered and dissolved into steam in the onslaught. Izuku trembled, his heart beating wildly in his chest—but it looked like it was working. The creature was too bombarded to counter-attack; it shrunk into itself protectively, curling up so that it seemed much smaller than Izuku had first thought.
It was making a different sound now—it was almost like a voice. Izuku, exhausted, breathed with great, panting gasps. He had a white-knuckle grip on the wood. But the waters were calming again. No more explosions followed, and the creature descended into the sea.
He was alive.
He cried into his white shirt sleeves with overwhelming relief flooding through him.
"Hey, are you al—…" a gravelly voice began.
Izuku sniffed, wiped his eyes dry and startled at the sight of Katsuki floating by the side of his boat.
"Deku," he breathed.
He had the same spiky head of blond hair. That same shade of scarlet irises that Izuku remembered. But he was muscular, with strong cheekbones and powerful arms. He wore shark tooth earrings and a matching necklace interspersed with pearls. On his shoulder, there was a tattoo, a black symbol that looked like stylised fins spreading from a Y-shape. Red and black bracers on his arms completed the new, older Katsuki's countenance.
The last time they'd seen each other was also the last time the sea had almost swallowed him whole. He had left Katsuki, judgemental and blaming, as he ran home with cold saltwater burning his insides. Now, eleven years later, Izuku could feel the weight of unresolved issues bearing down on the short distance between them.
"Kacchan." He bit his lip and averted his eyes, looking at the space where the sea serpent had raged instead. "What… what on earth was that?"
"He never should have gotten this close to the shore," Katsuki said with hardness. "I needed to drive him towards the surface, but if I'd have known there was a boat here…" He trailed off.
"He?" Izuku questioned.
Katsuki sighed, then disappeared. His lionfish tail flicked up into the air as he dove down. Izuku hadn't recognised it for what it was before now.
"Wha—?" Izuku's eyebrows lowered. Was he still that keen to dodge responsibility for his actions? "Kacchan!"
A second later, two heads popped out of the water. The unfamiliar one was pitch black, had a long, thin snout, feathery protrusions sticking out the back of his head and eyes that were barely discernible from the rest of his face. Izuku sprung into action, wielding his oar like a sword and scrambling to the other side of his boat until his back was flush against it.
"Get away from me, sea monster!"
"Deku. Deku! Calm down."
Izuku opened his mouth to object but got interrupted by the creature saying, "I cannot tell you how sorry I am that the darkness overcame me so absolutely." He hung his head in shame as Izuku boggled at him. "Now that Dark Serpent has been quelled, I am in my right mind again. My name is Tokoyami. I hope you can forgive me; I would never mean to bring harm to humans."
"Y-you're a merman too?" Izuku asked. He cautiously crept closer to get a better picture. Tokoyami had the head of a leafy seadragon, the torso of a human and the tail of a merman, a spindly appendage with more seaweed-like protrusions. Izuku jumped and dropped the oar. It clattered on the floor of his boat. "Gods, I-I'm so sorry! That was so offensive! I thought you were the—!"
"He was. I blasted him outta his uncontrolled form," Katsuki said.
"Yes, the magic imbued within me can bring forth a great, frenzied being of darkness," Tokoyami clarified.
"Get it now?"
"Um. Kind of? Why was he…out of control?"
Katsuki turned to Tokoyami, letting him answer. He closed his eyes and replied, "I was forcibly dragged down to The Depths by members of my previous clan. They intended to provoke Dark Serpent in the lightless, crushing abyss to attack The Reef. Unfortunately, they succeeded."
"Hey, you didn't touch The Reef, so don't fucking worry about it," Katsuki interjected.
The merman had always referred to his home as simply The Reef, but that was the only part of the conversation he was familiar with. "What? The Depths? You never told me about that before." Izuku stared Katsuki down; his expression remained angry and resolute.
"It wasn't exactly something I wanted to talk about, dipshit." He sure did swear a lot more than when they were kids.
"I just… never knew there was this much diversity in merpeople." Izuku decided he would write notes on all he learned today when he got home. Wait… "The market!"
"Hah?" Katsuki said.
"I-I've got to get back – oh gods, all the fish escaped. I've got to catch more. Heavens, how much time has passed? I'm going to miss all the buyers, damn it." He spun around as he agonised, checking everywhere on his tiny boat as if he could discover a huge pile of fish sitting somewhere in it. All he saw instead were his tipped-over buckets and a handful of feeble, gasping flounders.
"What the trench are you going on about, Deku? Your mum isn't going to give a fuck about that."
"We need to make an income, Kacchan!" Izuku shouted, increasingly desperate. Why did this have to happen at the beginning of the week, when demand was highest? What if it happened again? "This is my livelihood! And—and if your, your… merpeople politics stop me from fishing, I-I don't know what I'm going to do!"
"Shut up!" Katsuki slammed his hands down onto the water, emphasising his point with a sizeable pair of splashes. Tokoyami flinched. He looked like he wanted to be anywhere else but here. Katsuki jerked his head. "Tokoyami, go get something out of the treasury as reparation for Deku."
He nodded and wasted no time in leaving.
"You're not going to have your precious fishing expeditions interrupted cause I'm here. I'm not letting any more fucking deep-sea assholes get anywhere near my village, much less near the fucking backwater you live in."
"Oh, so I'm just supposed to trust you on that, huh?" Izuku countered. He ran his hand through his hair, making it even messier than it already was, then crossed his arms. Whatever connection he had inwardly been yearning for with the merman he had so admired as a kid, it certainly wasn't anything like this. Not with all the worst parts of his personality.
"Yes, you insufferable little…" He growled and shook his head. "I have a plan, okay? You don't need to concern yourself with our petty 'merpeople politics.'"
Izuku breathed in, counted to ten, breathed out. "Fine. As long as I can be on my way with something I can sell, I'll be happy, and we hopefully won't have to see each other ever again."
"Sounds ace to me. Where the hell is Tokoyami?" Katsuki dipped down and Izuku heard gargled shouting with accompanying bubbles. After a slight delay, that striking seadragon-man returned. He held a mermaid's purse in his hands. Katsuki swiped it and stretched his arm up to Izuku. "Here. Sorry the sea serpent made you lose your fish."
Tokoyami solemnly nodded his head as if Katsuki hadn't said it in the most disparaging tone of voice possible.
Izuku leaned down and took it. It was damp and felt like it was half-full of little beads. "Thanks," he said.
Katsuki grunted and gestured at him to go.
"Bye, Kacchan." Taking one last look at the merman who had changed so much and yet stayed exactly the same, Izuku dusted himself off, picked up his oars and started his way back home.
"Okay, mum, before I say anything, don't freak out. I'm fine."
Five minutes later, Izuku stood in an unescapable hug as his mother wailed into his green tunic.
"I-I-Izukuuu! I promise you'll never have to go out on that boat again, never, ever, ever!" she said as she bawled.
"Mum, no! I have to keep fishing, you know that. Now, come on, it's okay, really," Izuku comforted, wiping her tears away. "We have to get over to Aldera."
She lifted up the flap of her apron and blew her nose into it. "Without any fish?"
"Well, Kacchan gave me something in return for the…trouble. Here, look," Izuku said. He dug the small, dark green purse out of his inner pocket, sincerely hoping whatever was inside it would be enough to tide them over for the day. Who knew what Katsuki would consider fair compensation? He tore it open, took his mother's hand and poured out… a collection of blue gems. About ten pebble-sized jewels sat in her palm, each the colour of a cloudless blue sky an hour away from nightfall. Izuku's mouth fell agape.
"Izuku, are these…sapphires? Wha—we, this, I mean…" Her hand started shaking. "My—my gods, even if they're not, these could give us… H-how are we meant to value them?"
Izuku snapped out of his stupor, wracked his brain with his chin in his hand, then exclaimed, "Iida! His parents are jewellers. We can visit them on our way to the market."
"Oh, yes, yes! Izuku, this is fantastic. You really won't have to go out to sea anymore!" His mother clutched the gems to her chest as a wobbly smile overtook her face.
"Go out to…? But… Mum." He came to a decision. "I have to do something to pay him back."
She gasped, her expression turning horrified. "No, absolutely not! That boy almost got you killed two times over. Honey, your life is worth more than all the treasures in the world. You know that, right?"
"I…" He sighed. His voice turned small when he replied, "I guess. But, technically, he… he saved my life, too."
His mother placed the jewels down delicately on the table and stroked his cheeks with soft thumb pads. "You don't owe him anything. You can take them back if you feel like you do."
"No! No, let's…" He covered her hands with his own gloved ones and looked down at the wooden-plank floor. "You're right. About all of it. Let's just go to the market today and find a buyer."
The tension in her shoulders dropped and she brought him into another hug. "Thank you, Izuku. I don't know what I'd do without you."
Guilt gnawed at Izuku's insides as he replied, "Of course, mum."
