It started with a slip of the tongue.

Demyx went and lost his heart long after the first eight did, and the whirlwind of new sensations made it near-impossible to learn everyone's names right off the bat. He had to deal with the new and alien feeling of...well, not feeling anything at all, and in the middle of a crash course on Kingdom Hearts and Keyblades and hierarchy and magic and this whole not existing thing he just couldn't wrap his brain around, the last thing on his mind was knowing who was who. Except that was kind of important.

It made passing greetings difficult.

"Heyo, Shortstuff."

The dusky-haired young man that just passed him stopped dead in his tracks. It was kind of funny how, heart or no heart, he and Tall Blond Guy both had a knack for pulling off the most offended looks in the world, except where Tall Blond Guy just tended to yell at someone until their brains melted out of their ears, the newly-christened Shortstuff managed to announce his intent to murder with the glance of one uncovered eye.

"Beg pardon?"

It was kind of like the look Xigbar gave him sometimes, except not quite as creepy. Effective, though.

"Wait, I got this." And Demyx, in all his wisdom, thought he could cover his grave mistake with a thoughtful look, thumb and forefinger bracing his chin; then his forefinger went up like a flag, and...

Nope. It went down.

"Vixen?" Wild guess.

Shortstuff's eye rolled. "Zexion."

"Right! I knew that."

"Good." A quarter turn. "And you would do well to remember that that epithet suits you far better."

There was something very distinct about the way Zexion stuck his nose in the air when he walked away from a conversation. If it weren't for the overwhelming apathy that made pretending to care difficult, it might have grated on Demyx's ner- hey!

"What do you mean by that?"

"You heard me," Zexion shot over his shoulder. "Shortstuff."

"Woah woah woah woah woah woah woah."

There was something very distinct about the way Demyx stuck himself directly in the path of everyone who didn't want to give him the time of day. In Zexion's case, his apathy directly contributed to the false sense of amusement he got from the look on Demyx's face.

"I don't mean any disrespect, Zexion," despite that admonishingly waggling finger that Zexion hadn't seen directed towards him since Even caught him stealing ice cream from the freezer, "but you're not exactly in the position to be calling me short. Or anyone else, for that matter."

Zexion's expression went flat. "I have no desire to argue such an idiotic-"

"Am I right?"

"...No?-No."

"Prove it."

For a few long beats, Zexion had a look on his face like he was trying to sneeze but couldn't. "What?"

"You're a scientist, right?" Demyx crossed his arms, looking immensely pleased with his own logic. "So why don't we settle this scientifically?"

Zexion stared.

Two weeks later, there was a doorjamb striped in crooked horizontal lines from around the five and a half feet mark.

Two new lines were added each day. Zexion was diligent about the dates; Demyx wasn't, because he never knew for sure what day it was. He was, however, diligent about making sure his lines stayed just a smidge above the Schemer's at all costs, and when Zexion eventually found himself staring up at the marks, he knew something was horribly wrong.

"You're cheating," he hissed in the hallway.

Demyx, unfazed, trilled: "You're short."

Zexion learned he could stand on the tips of his toes, if he tried. Demyx couldn't, but he didn't have to; he realized he could just use a little more hairgel.

Zexion learned a new use for his books. Demyx also learned a new use for his books-well, he didn't have any books, but Vexen did.

Zexion didn't like that.

Demyx didn't like what he heard about the new outpost the Organization acquired until he found out he wouldn't be going to it. Larxene was, and for the first time since his name took on an 'X' Demyx thought he could really feel glad.

"I'll write you a letter every day," he snarked, just out of earshot from the others. "So you can still be all jealous when you're not here."

For the first time since his name took on an 'X', Zexion smiled.

"And I shall tear up every one."

Zexion never got any letters.

Two weeks later, Demyx had completely forgotten about the doorjamb striped with crooked horizontal lines. He didn't remember it until he was tasked with cleaning up the damage - alone, because his accomplice wasn't around to share in the responsibility. He worked from bottom-up, each carefully-written date jogging memories one by one through erasure, until one last line, in Zexion's handwriting, fell prey to the wet rag: I win.

For a moment, Demyx hesitated to erase Zexion's name.

It ended when he did.