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The water was dark, ominously thick, and nearly black. The kind of water that would frighten sensible, or even just normal people away, but Seishirou was not what one could call sensible or normal.
A monster hunter by very trade can't be either, since no normal or sensible person would put their life on the line to hunt. That's not to say Seishirou was reckless, hunting was just second nature, what he'd been taught from birth, and he enjoyed it. He loved traveling, experiencing the world and seeing different things and people. Even if, that at times became rather boring. People, themselves, were vast and varied, having endless thoughts, beliefs, and opinions. Despite that, in the end they generally were all the same, driven by the same desires and end goals as each other.
This job was nothing unusual in itself. A very common complaint. People complaining because their families or friends were suddenly grabbed by some kind of sea monster, with terrible green eyes, and dragged under the waves. From what it sounded like, the monster was a mermaid, or mermaids, which would at least be an interesting distraction from more monotonous monsters, since mermaids have the curious fate of being like humans.
Seishirou hummed, cheerfully, as he cast a fishing line into the water. He was sitting on the ledge of a rather dilapidated pier, made of wood long rotten and full of holes. People rarely came to these waters anymore, since the mermaids started hunting more frequently.
Seishirou predicted that it would be an easy job, as being an aquatic monster, mermaids would naturally be at as disadvantage if they were pulled ashore.
The finishing line, itself, bobbed innocently in the water, and then snapped. Seishirou blinked, curious. It could have just been a fish, but he doubted it.
Seishirou decided to test this. He'd caught a fish earlier for bait, and he tossed it into the water. It hit the the surface with a loud plop, and, in a movement so swift anyone with an untrained eye would have missed it, a hand grabbed the fish, pulling it under the water.
Seishirou smirked, and called, "Come out, I can see you." He stood up, and walked closer to the edge of the pier.
The wind was picking up, blowing Seishirou's dark hair into his eyes eyes, but despite this, he looked and felt rather cheerful, excited. He was poised, like a cat having sensed a mouse in the grass, ready to grab and kill his prey.
"Come out, it's okay," he called again.
The waters surface trembled for a moment, and something came to the surface. It was a beautiful, young boy, or something that looked like one. Short black hair framed his pretty, round face. His appearance reminded Seishirou of how people described supposedly angelic beings: etherial and androgynous.
If it weren't for his eyes, which despite being as beautiful as the rest of him, shimmered in a bright, almost toxic looking green, he may have thought the boy really was an angel.
"Who are you?" He tried to sound warm and friendly, as if he weren't planning on pulling the boy out of the water and ending his life. Humanoid monsters were way more fun than the more grotesque things he often faced. Though, that wasn't always a codifier for more interesting.
He looked back at him, bashful and embarrassed. He was completely adorable, and a new level of excitement bubbled under Seishirou's skin, when he heard him speak.
The mermaid boy stammered a bit, "Um? Uh, You want my name?" He paused, as if to consider if it was okay to give it or not, "My name is Subaru." He was blushing, his once grey cheeks a light pastel pink.
Seishirou had never seen anything as adorable as Subaru.
Subaru spoke again, "Thank you very much for the fish, um," breaking off again when he realized he didn't know the name of the man he was speaking to.
"I'm Seishirou," Seishirou cheerfully filled in. He was having the time of his life.
"Ah! Thank you, Seishirou-San," Subaru smiled, and gave a polite bow. He opened his mouth, showing rows of knife-like teeth, horrible blades, perfect for ripping through even the toughest flesh as if it were made of butter.
Subaru then took a bite of the fish in his hands, biting the head clean off, with a loud crunch, like the sound of someone breaking a stick. The fish's silver scales were dyed red with blood, as he chewed. He took more bites, eating the entire animal in only a few bites.
"Thank you," he said, after the last swallow, "The fish was delicious!" The young mermaid seemed very pleased, with no hint of irony or malice. It was only now, that his hands were fully out of the water, Seishirou could see that Subaru's hands were both webbed and clawed.
"Subaru-kun ," Seishirou spoke like he was talking to the most familiar of friends, "Do you know why I'm here?"
Subaru gave him a worried glance, "No, I don't."
"I'm looking for the one who's been eating all the fishermen and swimmers," Seishirou never lost his cheerful grin, "You wouldn't happen to know what happened to them, would you?"
Subaru's face dropped, his mouth pressed into a thin line, as he seemed to consider his options, choosing his words carefully, "What do you want to do with them?"
"Oh, I'm planning on killing them."
Subaru's voice wavered, he suddenly sounded nervous, "Who are you?" but his eyes gleamed dangerously, turning from bright green to a dangerous yellow.
"I said before, I'm Seishirou," He seemed totally unphased, as if discussing small talk for business. "Tell me, does it hurt when you kill people? Do you enjoy it?"
Subaru frowned, "Does it hurt when you kill animals? Do you enjoy that?"
"I feel nothing at all."
That response seemed to greatly shake Subaru, his eyes widened, both confused and horrified by the response, "Nothing?"
"Why would I? I'm not so sadistic to take pleasure in hurting things, but there's no reason to feel guilt in killings for food or survival."
Subaru looked down into the water, not meeting Seishirou's gaze anymore, "I hate killing things. I don't want to hurt anyone."
Seishirou, for the first time since their meeting, seemed genuinely taken back, completely confused by this response, "You hate it? Why? You need to kill and eat to live, so there's no reason to feel bad."
"Why would I feel good about hurting anyone? Why wouldn't it bother me?"
"You don't need need to feel bad," Seishirou comforted him. He'd grown a liking to him, in this short space, truly the most interesting person he'd ever encountered, "The most important thing you can do for the ones you care about is live. You don't need to cause senseless pain, but no creature can live without hurting others. People eat both animals and plants, and destroy the homes of both. Animals eat each other. Even the food someone eats is food someone else cannot. There's no completely peaceful life. I was hired to kill the mermaid who's been eating the people of this village, but you're just trying to survive, yourself."
"Thank you, Seishirou-San," Subaru looked at him, sadly, "And I have no intention of dying."
He lunged, like a leaping dolphin, light reflecting off his silver tail. His sharp talons scraping the wood of the pier, breaking one plank of it into splinters.
Seishirou jumped back, narrowly avoiding the strike. He pulled a long, wooden-looking rope from his bag and threw it.
It flew through the air, hitting Subaru in the head, where it transformed into a series of vines. They twisted themselves around Subaru's body, like snakes constricting their prey, holding him tightly in place.
Subaru screamed, and thrashed his tail violently, as Seishirou grabbed the now helpless man by his shoulders, and pulled pulled him onto the pier.
Now that he was out of the water, Seishirou could see his tail clearly. A deep, shimmering silver, with sharp, frilled spines running along to the frills. He ran his finger down it in curiosity, it was cold to the touch, and smooth.
Subaru bit him, sharp teeth digging themselves dangerously into his forearm. Blood flowed thickly from the bite, and if Seishirou was totally honest, he would've admitted the mermaid looked rather lovely with dangerous yellow eyes, and a bloody face.
"Don't worry," Seishirou laughed, "I won't kill you. You're the only person I've had any pleasure of talking to, so I'm letting you go."
Subaru opened his mouth in surprise, letting Seishirou go, "What?"
"As I said, Subaru, it'd be a shame to kill anything as interesting as you, so I'm letting you go. You should probably be a little conservative while hunting, though, for the next few months."
"Don't you care that I kill people?"
"Nope. I kill mermaids, so why should I?" Seishirou touched the vines and they snapped back, turning into a rope once again. He picked it up, and stuffed it into his bag.
"Will I ever see you again?" Subaru looked hopeful.
"Probably not," Seishirou admitted, "Unfortunately, though I like you quite a lot." He stood up and brushed off his legs, "Before I go, I want to know one thing. How did my blood taste?"
Subaru smiled, his mouth full of knife covered in blood, "The best I've ever tasted." He jumped into the sea, and was gone.
------
Seishirou woke up, groggy, and slightly annoyed, the next morning, to loud tapping on the door of his inn room.
He flung the door open, and put on a fake smile, despite not wanting to be disturbed, and frankly having no reason to be. The townsfolk should be happy, and let him get a late morning's rest.
The fake smile quickly turned into a real one. The person who was standing at this door was not a person at all, or at least, didn't use to be. It was Subaru, his silver scales and tail exchanged for legs. Around his neck was a large sapphire.
Subaru held up a piece of paper. On it was written, "I exchanged my voice for legs using the magic of the great Sea Witch Yuuko. I wanted to come with you."
Seishirou grinned, "Nothing would make me happier."
Subaru smiled at him, completely wordless, his face saying his happiness for him.