So-Ri-Kai- 50. You are born with the fingerprints of your soulmate somewhere on your body.
Soulmate marks weren't flashy. A set of five fingerprints spaced like the other part of their soul had reached out to touch wherever they showed up, growing to the rate of whoever they belonged to, just tiny, delicate whorls of color just a bit darker than the natural skin tone. Most people only had one set of prints. Sora, however, was lucky enough to have two.
"Can you see it?" he asked Selphie, shirt off and craning his neck around to try and see the mark that was forever out of sight between his shoulder blades. His first mark was on his hand, the marks spaced like a person was holding it. The second one he only knew about because his mom told him about it along with embarrassing stories about him playing in bathwater as a toddler.
At four and a half, he was no longer a baby and she needed to stop telling those stories even if it did make the ladies that visited smile and coo. Sora was getting to be big now; he didn't splash his bathwater all over anymore at all! …Well, not as much.
Selphie shoved his face back toward the wall. "Shush! I can't see if you're all squirmy, dumdum."
"I'm not dumb!"
Fingers sticky and cold from the popsicles they'd snitched from the freezer poked right under his shoulder blade and Sora flinched away.
"Hmm, yup. Ya got a mark. It's smaller than the other one."
"Ha! I told you I had two soulmates!"
"But how though? I thought you only got one?"
"I'm just lucky," Sora said with a grin.
Selphie pouted. "No fair that you get two and I got stuck with one." The expression lightened a moment later. "Oh, hey! D'y'know, I think Riku has two soulmates too!"
"Yeah?"
"Yeah! It's hard to tell cuz he always keeps his clothes on."
"I do too!"
"You don't have them on now."
"It's just a shirt!" Sora wrestled his shirt back on—inside out and backwards but that didn't matter. That just meant the itchy tag was on the outside. "How do you know he has two?"
Selphie sprawled on Sora's rug, picking at it. "Cuz he has one on his wrist—Wakka stole his wristbands once—but Tidus said he saw Riku's soul mark on his butt."
Sora burst into giggles. "Who has a soul mark on their butt?"
Selphie grinned. "Not us."
They laughed and Sora flopped next to her. Riku was really cool. And a good friend. Probably his best friend, but he didn't show Sora his soul marks. He said it was dumb to wave them about, but that was just Riku being dumb just because he was a little older than the rest of them. Well, not older than Wakka, but Wakka didn't act like he was older.
Sora thought soul marks were cool, so why not share them? They meant there was someone out there who would be your best friend. Sora was so, so lucky he got to have two.
"Where's yours?"
"On my neck," Selphie said, rolling on her belly and pushing up her hair so he could see the mark right below her hair line. The tiny whorls were dark, like the mole near them.
"Cool." Sora wondered what color the mark on his back was. Deep brown like on his hand? "D'you think we'll find out who they are?"
"Yeah." Selphie kicked her legs lazily. "Cuz my mama said that everyone in the island gets ta look at the finger print book and compare when they're, like, old."
"How old?"
"I dunno. Old. Like teenagers old."
"That's so old." Just being six was going to be old let alone waiting years and years. "And dumb. We should make our own book of prints and figure out who it is."
"Yeah?"
"Yeah!"
Four and a half years old, let it be said, was not an age where cleanliness or careful skills had a place yet. Sora and Selphie made a huge mess with Sora's paint set but they did get some finger prints in the end. Kind of. Sort of. (They had very sticky fingers and there was a lot of paper they could touch. Eventually some of them looked a little like the marks sort of looked.)
Four and a half was not, however, old enough to tell the difference between one set of fingerprints and the next.
Five and a half, on the other hand… Riku had been dragged into the literal mess because Sora said he wanted to find his soulmate so they could spend even more time together than if they waited. Riku thought that the only difference would be knowing who the person was, not actually having more time, but he didn't tell Sora that. He'd approached the matter with all the authority being almost six gave him and even got a book from the library about fingerprints and hung up the messy examples to compare with. He couldn't read the whole book well yet, but it did have nice pictures and tell what places to look for.
So that was how Riku figured out that Sora was his soulmate at six years old and proceeded to become even more best friends with him than they already were. Sora's words, not Riku's because Riku thought that just sounded silly. You couldn't get more than best friends.
None of them could figure out who the third pair of prints belonged to. Or they couldn't until a little girl showed up out of nowhere, one set of prints along her jaw and another clear as could be on her shoulder.
Kairi said that they'd all get married one day, which Tidus said wasn't something three people could do, and Sora'd said that they would just all be even more bestest friends which was even stupider than being even more friends and didn't really make sense at all. Riku didn't care what they'd be someday, he was just glad he had them now.
(Someday Riku'd tear himself apart over what the marks meant they were to each other. Someday he'd offer a hand to one soulmate and feel the phantom tingle of fingerprints on his wrist even as Sora failed to take it. Someday he'd think of a hand at the small of his back as he waited for Kairi to wake up. Someday he'd fit his fingers to his soulmate's marks and feel like he was coming home.)