It started with just the pink hair ties.

Jin noticed their buildup during Yamapi's "my hair is crazier than yours stage," on the counter in the bathroom, on the coffee table, holding closed bags of chips.

Yamapi would take them off and leave them laying around, and if teased about them always said, "Ne, i'm always looking for one anyway, aren't I?"

Eventually they changed his hair again, like always, short this time, back to black. But the hair ties stayed.

Next came an assortment of Yamapi's favorite and most comfortable jeans and shirts.

It took Jin a while to notice that one, though, since to be honest he'd borrowed most of them himself at one time or another.

And sure, he forgot to return something to Yamapi once in a while, but one day Jin was peering into his closet and wondering why he suddenly seemed to need his sunglasses, and finally realized that nobody could possibly be THAT forgetful.

"I ran out of space in my closet," Yamapi answered when Jin asked him about the clothes, not even looking up from the PS2. He was mashing buttons like crazy, well on his way to ruining Jin's third controller in six months. "You don't mind, right?"

Jin shrugged; he did have four closets in his apartment, and anyway Yamapi was sticking his tongue out of the corner of his mouth in concentration, so it was okay since he was borrowing something back.

The toothbrush was even more puzzling, but Yamapi was obsessive about brushing his teeth after eating, citing a stern mother and early childhood habit as an excuse, and it didn't clash with Jin's fuzzy purple bathmat or anything.

Jin left it where it was, leaning up against his in the fuzzy purple cup that completely matched the bathmat, and the next time he remembered that he had to replace his, he bought an extra pink one as well.

They were curled up in a sleepy knot in the middle of Jin's bed early on a Tuesday morning, when suddenly Jin sat bolt upright and exclaimed, "What's the date?!"

Yamapi snorted awake, blinking at Jin in confusion for a few seconds, before venturing, "The third?"

"OH NO!" Jin threw back the covers and bolted out of bed. "I'M LATE!"

He ran out of the bedroom, and when Yamapi struggled out of bed after him a few minutes later, he found Jin frantically rifling through the junk on his table, searching for a pen that wasn't lime green or glittery or actually a lighter.

"You're late?" he asked, rubbing his eyes, distracted by the fact that he'd only had three hours of sleep and that Jin was wearing nothing besides an expression of horror and a pink hair clip. "Ryo-chan said we should be using condoms, but I thought it was because of hygiene or something..."

"No, you moron!" Jin roared, snatching up his checkbook and pointing it at Yamapi like it was a loaded gun. "I forgot to pay my rent! I'm late!"

"Oh!" Yamapi started laughing, and Jin glared at him, hurt by Yamapi's lack of solidarity in his time of crisis. "I paid it last Friday."

"You..." Jin's hand dropped to his side, checkbook dangling. "What? Why?"

"Eh, you know." Yamapi scratched his stomach, looking away. "I always eat your food and make you throw my laundry in with yours...I thought it would be fair. Something nice."

Jin dropped the checkbook and the lighter, and pounced Yamapi, knocking them both to the ground, kissing away whatever other explanations Yamapi was trying to offer.

"You know," Yamapi grumbled when they eventually made it back to the bed roughly ten minutes before Yamapi's alarm clock would go off, "I'm pretty sure this is exactly what Ryo meant about the condoms."

"Shut up," Jin mumbled, face buried against Yamapi's neck and already dropping back off to sleep. "And don't let me sleep through the alarm again."

Yamapi spent the next ten minutes contemplating how often he would have knocked Jin up at this point if such a thing were really possible, and then the next twenty adding detail to the daydream until it was totally worth it when Jin woke up in a panic for the second time that day and tried to stab him with the hair clip.

"Pi?" Jin asked one night at random. They were sitting on his couch, a bowl of popcorn in between them, feet up on the coffee table, watching Teppei's newest drama and occasionally holding hands with popcorn kernels crushed between their palms. "Don't you ever go home?"

Yamapi let go of Jin's hand and shoved some popcorn in his mouth. He chewed slowly before answering, while Jin drew his knees up to his chest and tilted his head to the side, waiting for an answer. "Do you want me to go home?"

"No," Jin said immediately, noticing how Yamapi's shoulders relaxed. "But you have an apartment too, right? That place your stuff is?"

"No," Yamapi answered, then ate some more popcorn.

"Yes, you do!" Jin leaned forward, forehead crinkling up. "I've been there! It's the one three train stops down from mine, with the pink doormat and the five hundred pairs of shoes, remember?"

"No," Yamapi said again, then when Jin started look actually worried, added, "I mean, I did have an apartment. But I've been living here, so I stopped. Having it."

"But..." Jin glanced around. "Where's all your stuff?"

"You might have noticed the pink doormat when we answered the door for the pizza," Yamapi said. "And as for the five hundred pairs of shoes, you haven't been in your fourth closet for a while, have you?"

Jin looked over his shoulder at his bedroom, then back again with a skeptical expression. "Did Shige put you up to this?"

"Jin," Yamapi said gently, leaning over to hold Jin's head still with two butter-greasy palms against his cheeks, "I've been living with you for the last two months. You haven't noticed?"

Searching Yamapi's face for Shige-trickery and finding none, Jin finally gave Yamapi a sheepish smile and shook his head, moving Yamapi's hands back forth. "No. And yuck, now my face is all buttery."

"I'll help," Yamapi declared, pulling his hands away and leaning over to lick a stripe along Jin's cheekbone. Jin giggled and kicked the half-empty popcorn bowl out of the way so that he could yank Yamapi on top of him, and they never did find out whether Dr. Koike saved the premature twins' lives or not.

They were a little busy, Yamapi undoing the buttons of his favorite shirt and pushing it off Jin's shoulders, and Jin working his hands under the waistband of his favorite jeans against Yamapi's skin. It felt comfortable, familiar, and at the same time had a new thrill tripping up Jin's spine, one that he couldn't quite figure out for a few seconds, but then it dawned on him all at once as Yamapi grabbed the throw pillow that fit under Jin's hips perfectly without even looking for it.

"We're living together!" Jin beamed up at Yamapi, his heart racing in his chest, and when he reached up to slide his palms over Yamapi's chest, his heart was doing the same thing.

"Glad you finally noticed," Yamapi answered, condescending and affectionate, and then he wrapped his fingers around Jin's cock and stroked him just the way he liked. "Because I think cohabitational sex is just about the only kind we've never had."

"Is it any different than the other kinds?" Jin wanted to know, shoving his jeans down Yamapi's hips and scootching down until they were settled in the dip they'd worn in the couch.

"No." Yamapi reached under the couch and fished out the tube of lube they hadn't bother chasing after two days ago. "It's just that when we shower later, I'll know where your towels are."

"And I'll know where your toothbrush is," Jin agreed smugly, then cut off with a groan as Yamapi slid slick fingers inside of him.

It was like coming home, Jin thought hazily as Yamapi slid inside him by degrees, Jin wrapping arms tight around Yamapi's shoulders and tasting the flutter of Yamapi's pulse in the dip of his throat.

"I'm home," Yamapi whispered when his hips were snug against Jin's, voice shaking but hand steady as he smoothed Jin's hair back from his face, and suddenly they were both grinning so hard it hurt.

"Welcome home," Jin answered, because there were certain things that had to be done properly, when people who cared about each other lived together.

And then Yamapi started to move, and Jin dug his fingers into Yamapi's skin and curled his toes against the nubbly fabric of the couch, and both of them mumbled a lot of things that not even people who cared about each other and lived together would admit to afterwards.

"You get to vacuum the carpet!" Jin cheered later, when they were snuggled in a pile across the couch, both of Yamapi's most comfortable and favorite shirts on the floor and the afghan that Yamapi's mother had crocheted thrown over top of them. "Cause if you live here you have to do chores!"

"I'm the only one who ever vacuums the carpet, you ass," Yamapi replied, kissing Jin again just as Jin was getting on his really good indignant face.

Jin didn't mind. Now that Yamapi and he were living together, they had plenty of time for all of Jin's really good facial expressions.

"Hey," Yamapi said, lifting his head just far enough to squint at the coffee table. "Have you seen any of my hair ties?"

Jin held up one hand, the elastic pink band snug around his wrist. Yamapi laughed, rolling the band up just far enough to kiss the spot where Jin's skin was dented, then left the hair tie exactly where it was.