It was actually Naruto who thought of leaving notes first, but then he remembered his terrible handwriting and how little he understood even the neat characters on their class' chalkboard, and he immediately shoved the idea aside in favor of just being very quiet during their switches and hoping no-one noticed.

(Of course, everyone noticed, because Hinata Hyuuga pranked Kiba Inuzuka no less than three times in four months, and Naruto Uzumaki frequently looked incredibly embarrassed and apologized profusely even when he'd done nothing but forget to hold the door open.)

Once Hinata thought of it, she almost slapped her forehead at how simple the solution was. Just keep a pen and paper with them and make sure to let each other know what they'd done while they were in each other's bodies and the problem was solved.

Or, at least, it had been simple to her.

"Naruto," she whispered to a pale ear framed with black hair during a study hall, "Can you try and write a little neater? I can't read the notes you leave me."

Her original face turned incredibly red, small dark eyebrows pointing downwards in an irritated frown, "That is neat!"

She shushed him when sensei turned towards them, then scooted closer. "Your 'ma' and your 'ah' always look like they're the same thing. And what do you mean by this?" She pointed at a hastily-scrawled cross in his sentence, a frequent bringer of confusion for her, since it was neither 'na', nor 'me', nor juu, which it most closely resembled. "It looks like 'ten'."

"It's 'ho'!"

"No, it's not," she said, "'Ho' is like this." She wrote it carefully in the corner of his worksheet.

He blinked at it, then looked at their workbook and blinked again. "Huh. That makes sense. But that's not how it is on the chart I got last year."

She frowned, "It looks like this on my chart."

"Naruto Uzumaki!"

She didn't react until he nudged her and she realized that, right now, she was Naruto Uzumaki.

"H-hai?" she said warily.

"Stop bothering Hyuuga-san! If you can't do work, then go stand in the hall."

"S-sorry," she said quietly and walked quickly out of the room, proceeding to stare at the wall.

A few minutes later, she was once again staring at the paper with her name on it. She huffed and reached into her pencil case for an eraser. Not only did Naruto have terrible handwriting and poor knowledge of katakana, he also barely knew theory! Once all the corrections had been made, she reached into her pocket for the notepad.

Among smudged kanji and misspelled words was a tiny picture of what must've been her (or him in her body) with a grinning whisker-cheeked Hokage next to her under a spiral-sun. No-one had ever drawn a picture for her before. She wished she'd written something nicer in her notepad - it was just a reminder that he'd received detention and would need to attend it after school.

If she was still in this body, she could use her allowance and get him a snack to share afterwards to make up for it. What was his favorite food?

The next page was covered in doodles of ramen.