Well, It's not a mermaid AU but that sounds interesting! I might think about that one!

As always, I don't own SNK or any of its characters.

At the age of 9, Jean learned that soul mates existed.

It was summer vacation and his parents had told him they would be spending two months at the beach in Mexico. Jean was never a fan of the beach (It was hot and the sand got stuck in uncomfortable places) so he already had very low expectations for this trip.

On the very first day, Jean had gotten bored and had wondered away from his parents. He ended up at the hotel's buffet and his childish logic lead him to hiding under a table.

But he wasn't alone. A blonde kid who seemed to be maybe a year younger than him was sitting under the table with a book. When Jean lifted the tablecloth to sneak underneath he was met with a pair of blue eyes that had suddenly reminded him of the ocean nearby.

The blonde blinked in surprise but immediately smiled. He suddenly took Jean's hand and ran out of the table and towards the beach.

Their connection was instantaneous. They didn't even know each other's names and they were already best friends. Jean's dislike of the beach went away completely as the boy told him hundreds of facts about the ocean.

It was between a game of tag that Jean actually asked for his name.

"Armin!" Said the blonde before tapping him on the back and running off with a loud laugh.

From that day on for two months they were together at every moment. They would walk by the waters edge, collect seashells, and make sandcastles. They would look at fishes and then look at Armin's books and try to find out what type of fish it was.

One day the two boys rested on a towel over the hot sand.

"You know what my dream is, Jean?"

"Hm?"

"I wan't to live in the ocean!"

"You can't! You would have to be a fish!"

"I'll find a way. You'll see."

Jean grunted and looked to the side feeling slightly upset. He didn't want Armin to go live in the ocean and leave him alone. Suddenly the blonde took hold of his hand and laced their fingers together.

"You're coming with me right?"

"Huh?"

"To the ocean! I'm not going without you!" The two boys looked at each other. Jean mirrored Armin's bright smile.

"Yeah! We'll always be together." Armin giggled happily.

"Forever!" He agreed. They spend the rest of the day holding hands (literally the rest of the day, Armin even asked permission to sleep over at Jean's hotel room and they fell asleep like that).

They became a sort of famous sight on the beach. The people working there were happy to see Armin and Jean (always together, they never saw just one of them). They sometimes gave the kids free souvenirs of clues as to where the prettiest fish would gather.

They started kissing by the end of the first month. The tourists who saw them thought Armin was a girl and they found it very endearing so they never told anything to their parents.

There was a stand for making necklaces out of shells. They each made one for the other and wore it every day after that.

"Remember! These are a promise!" Armin said when he placed the necklace over Jean's head.

They would lay on the sand and feel as happy and blissful as only children know.

"What is our house in the ocean going to look like?" Jean asked once.

"Well I haven't planned that out yet. We can make it out of seaweed… or coral! Coral is nice."

"Should it have stairs?"

"We'd be under water so we would swim so we don't need them." Jean nodded at Armin's words. He looked at the sea absentmindedly.

"Do fish get married?" He wondered. Armin sat up straight.

"Of course!" He said with fire in his eyes. "Fish fall in love and get married just like humans!" Jean sat up and giggled.

"So you aren't going to ditch me once we're fish?" Armin jumped on top of him and hugged him tight.

"Nah! We'll get fish married, I promise."

"Ok."

Those were the happiest two months of their lives. Armin's parents were afraid of the day they would leave. They knew their son had become far too dependent of Jean and that they should have separated them sooner. Now they thought it would be no use to frighten him about their due departure so they just let him be until that day.

Jean's parents, on the other hand, kept reminding him that they would be leaving soon and that he would have to say goodbye. He didn't listen because he felt like they were stupid if they thought he was going to leave Armin.

On the day they were leaving, Jean's parents packed all their bags but Jean ignored them and went to Armin. The two of them walked by the water's edge. Armin was happily telling him about jellyfish when both of their parents appeared before them.

"It's time to go home, Armin." His mother tried to say calmly. Armin was confused and thought they meant their beach house.

"But it's morning! Is a storm coming or something?"

"No, sweetie. We mean home in England."

"You too, Jean. Japan is very far away."

Armin was smart and immediately caught up to the situation. He pressed Jean's hand as a signal that the boy understood.

Run

They both ran off fast, each to the opposite direction as to confuse their parents but both knowing exactly where they were going. They met up at a cave they had discovered a while ago. Armin was almost in tears.

"We said forever, Jean! You promised!"

"Don't worry! They're not taking us away."

They hid there and held each other and talked about what their life in the ocean would be like.

Some workers from the beach found them but it had taken all day. Both boys tried to run off again but were caught. Armin was crying rivers and he stretched his arms towards Jean. Jean tried to reach him but even if he was stronger than Armin he wasn't strong enough to fight a grown man. Soon they were brought back to their parents who lost their grip on both of them. The kids, instead of running away, ran to each other and desperately clung to one another because those few seconds had been pure agony.

Their parents weren't heartless but they had just lost their flights and they weren't in the best of moods. They forcefully pulled them apart and practically threw them into their respective cars.

"Jean!" Armin kept crying out through the car window. Jean watched Armin's tear streaked face as the car drove off and his heart exploded with pain.

We said forever…

"There must've definitely been a better way to handle this." Armin's mom muttered.

"He'll get over it within a week." Except he didn't. Once he stopped yelling his friend's name, Armin curled up into a ball and sobbed the whole way feeling more alone than ever in his life. He entered a sort of depression. He stopped going outside, playing, or even reading. He would just lie on his bed and hold onto his shell necklace. Every day he dreamt of the ocean and of Jean.

His parents were really concerned and they tried to get him professional help but all the doctor could say was the obvious.

"He just misses his friend. All you can do is try to help him to move on."

His parents were at a loss of what to do. One night, while Armin was sleeping, they set on his bed some of the books he had taken to the ocean during his trip. When he woke up and saw them something made him open them and begin to flip them.

He remembered all his times with Jean, but the memories did not bring sadness. They brought determination.

"Jean promised we would live in the ocean! I have to stop being sad and find a way to get back there!" So he found a new goal. He would learn all there was to know about the sea and go back when he got older.

"Jean will be there. I know he will!"

Jean tugged at his shell necklace with one hand as he read the exam question. It was a habit he had acquired over the years: tugging at his necklace. He did it when he was nervous or when he was thinking. At the moment he was feeling both ways. Finals were very stressful indeed.

He looked out of the corner of his eye at his best friend, Marco. The freckled boy seemed to know what he was doing and Jean swore under his breath.

Come on! It's the last exam of the year!

His fingers kept rubbing over the little seashells. He took a deep breath and began to write.

"It's over! Summer vacations are finally here!" Jean wished he could share Marco's enthusiasm. He simply felt drained after all the late night studying and his breath stank of coffee. "We should go get some lunch to celebrate!" Well it's not like Jean had anything better to do. He agreed and they both headed to a nearby café.

They took a seat at a table and began to chat idly.

"So, do you have any plans for the summer?" Marco asked.

"Not particularly." Jean muttered, absentmindedly tugging at his shell necklace. He didn't notice the way Marco watched him.

"I always wanted to ask you about that necklace." Jean jolted at the sudden mention of the precious object. He looked at Marco with a frown. "I've never seen you without it and you always seem to touch it when you subconsciously search for comfort." So Marco had given this a lot of thought.

Jean looked away. It was true, he wore that necklace every day.

It's the only part of him that I have left…

"I never asked you because the last time someone did you looked like you were about to punch them." Yeah, Jean remembered that. The guy asked why he never took that 'cheap souvenir' off and Jean was sure his eyes had spelled murder.

Jean stayed quiet. He didn't want to talk about it. He had never told anyone about Armin. It was his most precious memory and he wasn't going to share it with anyone. Marco watched his expression carefully.

"Did someone give it to you?" Jean looked away rather quickly. Marco's eyes widened. "Did someone make it for you?" The taller boy didn't like where this was going. He took a sip of his drink to distract himself. Marco was silent for a moment. "Did that person die?" Jean choked on his drink and coughed violently.

"Don't even say that!" He yelled with actual panic. The thought of Armin being dead had never crossed his mind but it was not something he ever wanted to contemplate. Ever.

"Sorry." Marco muttered. "But at least I got 2 out of 3 right." Jean crossed his arms. He was really getting annoyed.

"That's enough, Marco. Change the subject."

Although he didn't have any plans for the summer there was an obvious place he wanted to go to. A place he had dreamt of going to for years already, but he knew it was no use. His father had lost his job not even a week after they returned. Every summer, Jean had begged his parents to take him back but his family never seemed to be economically stable. They were never able to afford another trip since.

Jean sighed as he lay on his bed. He took of his necklace and looked at it. Of course Armin was always at the back of his mind, but what Marco had said had him not being able to think of anything else.

At dinner, Jean can't stop himself from asking.

"Hey, mom. Do you remember the name of the hotel we went to? You know, in Mexico?"

His mother looked thoughtful for a moment.

"Great oasis? Something like that…" Her eyes suddenly sparkled and she turned to her husband. "I just remembered that we saw a starfish in those vacations! Remember? It was so beautiful!"

Jean wasn't listening anymore. In his mind eye he was trying to remember the way the hotel looked. He was mostly outside exploring the beach with Armin but there had been one day spent snooping around the building. It had been fun but there hadn't been that much to see so one day had been enough.

"I think we took a video of it! Let me see if I can find it." Jean's father spoke before standing up from the table. Jean's mother had a dreamy expression.

"Wouldn't it be nice to go on a nice vacation again?" Jean was surprised that she was saying this. For years the topic of vacations had been a sore subject considering Jean never truly forgave them for taking him away from Armin and it reminded them of the money they no longer had but Jean hadn't insisted for around 3 years now so maybe that had toned it down. Even so, his mother knew how he truly felt.

His father found the video and played it. The image of his mother excitedly holding a live starfish in her hand appeared. Jean watched, slightly bored. Then out of the corner of his eye he saw something that made him gasp. At the very corner of the videoscreen there was his 9 year old self building a sand castle with Armin. Jean was laughing and smiling in a way that he hadn't done in years. Suddenly the blonde jumped on him with a giant hug and they both fell onto the sand, laughing.

Jean hadn't seen that face in years. Although it had left a permanent mark in his heart, the memory of the physical person had been fading away. Now there he was, and suddenly all of Jean's memories were much clearer. He needed to see him again. He needed to find him. Jean stood up violently.

"Mom. Dad. I'm going to Mexico."

He spent the next 2 weeks working like crazy. He sold many of his things, offered to wash people's cars, walk their pets, cut their lawn, anything. He wanted to raise enough money to get his parents to come with him but they insisted that they would be fine.

"Go find me my son in law." She said with a wink.

Marco was a lot of help. His father had some contacts and they were able to give him a cheaper flight ticket. Soon Jean was nervously rubbing his necklace as he sat on the plane.

What am I doing? What are the chances that he will even be there?

But those thoughts were interrupted by the memories he had of the blonde boy who had held his heart for 8 years.

This is something I have to do. If only for the sake of our memories.

Being there made his chest ache. Every little thing brought memories and emotions hitting him like the waves hitting the coast. He found himself finding comfort in the nostalga though. It hurt that he wasn't given the chance to have a future with this person, but they had met and they had been happy.

He walked by the water's edge and he could almost hear that bubbly voice spewing one fact after the other about their surrounding.

"Where are you…?" Jean whispered fondly. He watched the water and gave a small chuckle. "Maybe you figured out how to turn into a fish and left without me."

"Hurry! Hurry!" Jean's attention was caught by the yelling. He turned to see a crowd of people watching something. He decided to near it.

There were people running from a circle in the sand to the ocean. That was when Jean realized that it was a turtle nest and the people were caring little baby turtles and taking them to the water.

Jean joined the crowed and smiled when he saw the little turtles. The people running were very focused on their task. Finally the last turtle was in the water and everyone cheered. The runners were able to look up and smile in relief.

That was when Jean's eyes landed on one of them. He had long-ish blonde hair tied into a ponytail and bright blue eyes.

And that smile. It hadn't changed.

Jean stared, mouth open wide. His heart was beating so fast he thought he was getting an attack. Finally the blonde noticed he was being watched and made eye contact.

Armin froze. His eyes became wide with shock and disbelief. The look suddenly became one of pure joy and Jean could wait no longer. He took one step to run towards the blonde when suddenly another brunette (one of the ones who had been running) spun Armin around and kissed him.

Jean froze and even Armin looked shocked. The blonde turned back and they kept looking at each other, silently agreeing to speak about that later. Right now they just needed to be with each other.

Armin quickly made his way towards him. Jean began to move as well. They both stopped a few steps away from each other, like they still can't believe they were actually there. Then Armin broke into a run and let out a breathless laugh as he hugged him. Jean held him tightly and buried his face and hands in Armin's hair, efficiently undoing the ponytail.

He's here! He's actually here!

They stayed like that for a few seconds before pulling away to look at each other. Jean wiped Armin's tears and the blonde smiled. He took hold of Jean's hand and lead him through a path that seemed very familiar. Soon they found themselves in the cave they had discovered all those years ago and where they had hid from their parents the day they were separated.

Jean took hold of Armin's face with both hands and looked at him intently. He traced his features with his fingers. His eyes, his nose, his lips.

"Look at you…" he whispered fondly.

"Jean." How he had dreamed of hearing Armin's voice again. The blonde placed his hand over Jean's. Those blue eyes landed on his necklace.

"You still have that…" Jean nodded. He realized his own eyes were getting watery.

"You?" He put a hand under the colar of his shirt and out peeked a shell necklace.

"Always." Now it was Armin's turn to trace Jean's face. They were so close that they were breathing the same air. "You've grown."

Jean laughed.

"Yeah 8 years will do that to you." He laid their foreheads together. "I've missed you. I've missed you so much." It sounded raw and full of emotion. He held Armin's chin and leaned in.

With difficulty, Armin pushed him back lightly.

"Jean… we need to talk first." The brunette sighed and let his forehead fall against Armin's again. He looked into those blue eyes and they held so much affection that Jean doesn't fight him.

"Alright. You tell me your story then I'll tell you mine." He buried his face against Armin's neck. "…then we can get fish married." He muttured. Armin laughed. A pure and perfect sound.

"You didn't forget that part."

"It's my favorite."

They sat down in front of each other. Armin told him about how when they were separated he had been sure that Jean would be here so he spent the last 8 years studying to become an expert in marine science. He applied for a job here about a year ago and they gave it to him even without finishing high school.

"I was so happy to be here. I felt so hopeful that I would find you. But as the days went by It hit me that maybe you would never come." Jean felt awfully guilty.

"I had promised that we would live in the ocean together so I also realized I couldn't stay. Not without you." Armin paused. He had been looking away all this time but now he held Jean's gaze.

"Eren stopped me at the airport." In his mind, Jean could see that boy kissing his Armin and an intense anger filled him. "He told me that he loved me and begged me to stay. He had been my best friend here and we had become close… I really do love him." Jean's breath caught in his throat. "I thought that maybe it was fate that you weren't here. Maybe Eren and I were meant to be together all along. I stayed here with him but… it was never the same. I was happy but… I wasn't. I still felt that ache I my chest. He wasn't… you. I've never loved anyone in this world as much as I love you."

Jean touched Armin's cheek again, before leaning in and kissing him. Armin was soon on top of him. It wasn't violent or desperate, but deep and full of longing. They were both filled with the feeling of suddenly becoming alive as if they had been dead all this time they had been away from each other.

"You're stuck with me forever, ok?" Jean held him tightly. Armin giggled.

"Ok."

After kissing a whole awful lot, they laid next to each other, holding hands like they used to.

"Your turn to tell your story."

So Jean did. He explained how his dad lost his job and they never had enough money to travel again. He told Armin about the video and how that had inspired him into working to being able to afford the trip.

"I didn't really think you'd be here, but it would've been like being with you again."

Armin's phone began to ring. The blonde sat up and took it out of his pocket.

"It's Eren…" Jean was silent. He watched Armin's face. "I'm sorry…" The brunette felt pained. What if Armin picked Eren over him? Hadn't they just said they would be together forever? Was that promise going to be broken again?

Suddenly Armin's phone went flying out of the cave and Jean realized it wasn't him the blonde had been apologizing to. Armin moved towards Jean and snuggled against him.

"I guess the first thing I have to do is break up with him…" he sounded sad but not unsure. Suddenly his face became worried. "but, Jean… what are you going to do? I mean, you're just here for vacation-"

"I'm staying."

Armin blinked in surprise.

"But your school! What about your studies?"

"The truth is I'm not really good in academics. There's never really been a job I've wanted or something I've wanted to do with my life." He looked down at Armin. "The only thing I've ever truly wanted is to be with you."

Tears were leaking out of the corner of those blue eyes.

"Are you sure?"

"Hell yeah. I'll be the freaking towel guy. I don't care. I'm not leaving you."

The two held each other close and smiled because they knew that this time "forever" would be true.