Written for Runefallstar's request for 838 college AU.

It was Biology. It had to be Biology.

He had ignored the science requirement in his schedule plans as if it were merely dust in the corner he meant to sweep up one of these days--as if ignoring it for long enough would eventually, mercifully, make it disappear.

It did not.

And that was how Kouryuu Sanzo came to be sitting in the University Center, behind a frustratingly tiny school desk, across from Cho Hakkai.

Kouryuu knew he was in for it, on the very first fucking day of class. He knew it right when that guy from the debate walked in, took one look at him, and zeroed in on the desk next to him like the finest military strategist. It did not help that the guy happened to a natural at Biology when Kouryuu was, well, not. It also did not help that Kouryuu was a complete failure at not looking, not thinking about looking, definitely not thinking about looking at Hakkai's slender fingers absently stroking the clean edge of his own notebook during every single lecture.

In a better mood, he might have enjoyed the pearly grey clouds piling up in the tall windows; instead, he saw the mess of papers piling up on his desk and had the sudden impression that they were building towards an attack.

He tried not to think about the fact that Hakkai was giving him the exact same impression.

"A knowledge of Chemistry," he'd been saying, "can help us reach a deeper understanding of Biology and its various processes. You'll need to read Appendix B closely, as it quite fully covers atomic bonds and chemical attractions." It was worrisome to witness, that mischief he had honed sharply enough to frighten any human being.

"I don't understand this science crap," Kouryuu gritted around the unlit cigarette clenched between his teeth. He didn't understand at all.

"Ah?"

He had expected at least a reprimand for swearing, paired with a gentle encouragement to either finish his studies or face his own ruin. The only thing that did happen was a flicker of expression so small that he thought it could have been only a trick of the light.

Hakkai carefully squared his stack of flashcards, flipped over the next card, and began writing.

In complete and patient silence.

It wasn't a cold or even uncomfortable silence; it was the kind of silence that made Kouryuu shift in his chair and curl his toes, made him feel as if something was about to happen, made him feel as if all the atoms in the air were buzzing around at the same time. He stared at the woodgrain showing in the gap between two papers, and resolved that he could simply wait it out.

After six minutes and thirty-two seconds, Kouryuu pulled out Principles of Biology, turned to Appendix B, and held out his hand.

"Highlighter."

After a few small sounds--he somehow couldn't make himself look up from the book--he felt the highlighter being pressed into his palm and then, so lightly and quickly that he almost didn't feel it, the soft skin of Hakkai's knuckles brushing across his fingertips.

"Science," Hakkai commented as he adjusted his glasses, "is impossible to ignore."