Rei liked to keep his life neatly compartmentalized. He woke up at the same time every morning and came home at the same time every evening. He ate to maximize optimal nutrition intake, he exercised for the recommended hours a day, and he studied all subjects evenly so as to enrich his mind and leave no weak points.

In Rei's experience, all events made a clear line from cause to effect, and it was his firm belief that, if a person let logic rule instead of emotion or fantasy, then there was very little they couldn't be prepared for. Needless to say, he didn't like surprises.

"Rei-chan! Morning!"

Nagisa waved at him from his seat. Rei was standing, one hand gripping the ceiling handle, rocking gently with the motion of the train.

"Good morning, Nagisa-kun," he replied in a softer tone, hoping to influence Nagisa to lower his own voice.

"Are you running the last leg to school again today?" Nagisa asked, not taking the hint.

"Of course." Rei didn't understand why Nagisa had even asked.

"I think I'll come with you this time."

Rei hesitated.

Nagisa tilted his head. "Is that okay?"

"…It's fine."

It didn't make any sense. Some days Nagisa would beg to tag along, swearing to the heavens that he wouldn't slow Rei down so please could he run with him. And then others he wouldn't even mention it — just wave at Rei from the window in the brief moment before the train left him far behind.

It was the inconsistency that bothered Rei. It left him constantly on his toes. He didn't like surprises, and ever since Nagisa barreled into his life, there'd been nothing but.

Like how he was suddenly a member of the swim team, despite being certain he would join track. Or how he'd humiliated himself in a hundred different huge ways in the past few months to the point he was becoming used to it, when usually just bumping shoulders with someone by accident had him reprimanding himself for the rest of the day. Or how sometimes these days he'd catch himself thinking that it was almost like he was a completely different person to whoever he was before.

Rei narrowed his eyes at the oblivious, grinning boy in front of him. All of it was because of him. He has no idea what he's done to me.

Chaos Theory

It was a small moment that wasn't that remarkable on the face of it. They were in the middle of club practice and Rei had just beaten his best time. It was pitiful compared to the others, but they still acted like it was a huge achievement.

Rei felt touched by their earnest kindness, and decided it was okay to think of this as something to be proud of. Makoto and Gou both cried out their congratulations, while Haru gave him a small nod of approval, and Nagisa jumped up and hung all over him as usual.

It was in that moment, with Nagisa's limbs tangled around his waist and shoulders, that Rei felt a jolt of… something. Excitement, but not like the excitement he felt at beating his best time. It was more… oh. Oh no.

Rei froze, and Nagisa took no mind, continuing to wriggle and clutch at Rei's body. The terrible excitement grew, and Rei gave Nagisa a firm shove, toppling him back into the water. Nagisa just laughed and swam away, totally unaware of the incredible mental meltdown he was leaving in his wake.

I am absolutely not attracted to Nagisa.

It was the millionth time he'd repeated it, but the mantra wasn't helping.

This was gravely concerning. Rei had a lot of plans laid out for his high school life here, and none of them included this horrific new development. Rei was going to practice hard and enjoy success as part of the swim team (modified from the original track team plan), he was going to do well in his exams, and then in his third year a cute girl with shining eyes and flushed cheeks was going to bow low and confess to him, they would start dating steadily and perhaps even make a promise to continue seeing each other in university.

In order for his perfect high school life to be realized, Rei was going to have to get over this weird brush with theoretical homosexuality as soon as possible.

And Rei put his best foot forward — he really did — but it was barely a week later that things went from bad to infinitely worse.

It was annoying enough that he couldn't stop that stupid jolt of excitement popping up at the most inappropriate times — when Nagisa was licking the moisture from an ice pop, or rubbing his face on Rei's shoulder, or even just smiling with the sun behind him — but then he found himself preparing to jog to the train station after school with Nagisa once again in tow.

Despite his shorter legs, Nagisa was good at keeping up. But he must've had a lot of energy in reserve that he wasn't using for studying, Rei reasoned.

"Hey, Rei-chan, are you feeling okay?"

"Why do you ask?" Rei said, then added, "I'm fine."

"Um… well…"

The sound of Nagisa's footsteps ceased, and Rei came to a halt and turned back towards him. They were both breathing a little heavily from their efforts.

"You've seemed a little stressed out these past few days." Nagisa scratched his cheek. "I was wondering if it's something to do with the club."

"It's not," Rei said, then added, "I'm not stressed out."

"Okay. That's good." Nagisa smiled. "Because we're all really happy you decided to join, you know."

Rei blushed, feeling awkward. Nagisa looked a little embarrassed, himself.

"I'm really glad it was you, Rei-chan," he said, quieter this time.

Something jolted through Rei, but this time it wasn't excitement. It was far, far worse.

I might actually be in love with Nagisa. He felt sick.

Catastrophe Theory

The crushing pressure of it all began to eat away at Rei's daily routine. He started oversleeping — sometimes waking up from vivid, messy dreams — and suddenly studying was impossible to do in more than ten minute bursts, with frequent breaks to turn over the Nagisa situation in his mind one more time.

His grades began to suffer. His swimming began to suffer, and that was unforgivable. He was already pulling the team down — he couldn't afford to be getting slower.

While he worked on a more long-term plan for righting his life, Rei found that the short-term idea of avoiding Nagisa whenever possible was working fairly well. Less of those troublesome jolts to worry about. Of course, the knowledge that he was being unfair to one of his friends — no, all of his friends, really — was starting to weigh him down. There was no perfect solution to this problem. At the moment, Rei's best hope was that, if he spent enough time away from Nagisa, maybe the problem would go away all by itself.

"Rei-chan! Rei-chan!"

Of course, that would only work if Nagisa would stop seeking him out outside of swim practice.

"Jeez, Rei-chan, it feels like I haven't seen you in ages." Nagisa ran up to him in the hallway, during the changeover from second to third period.

"You saw me yesterday." Rei knew he must sound inexplicably cold. "And you'll see me later today, at the pool."

"Well, yeah." Nagisa shuffled from foot to foot. "I just meant… Mm. Hey, can I run to the station with you after practice?"

"Um," Rei hedged. "Actually, I have somewhere to go."

"Really? Where? Can I come?"

"Don't just invite yourself along!" Rei snapped.

Before the weirdness began, this would've been no big deal. Rei yelled at Nagisa all the time. Nagisa enjoyed making him do it. But with things the way they were, Nagisa didn't look smug. He actually looked a little hurt.

"Rei-chan, you're acting really strange lately," Nagisa murmured, then looked Rei directly in the eye. "And I think I know why."

"Y-you do?" Panic shot through Rei, making him ramrod straight and drawing a line of cold sweat down his back.

"Uh huh! Rei-chan has… a secret girlfriend!" Nagisa winked, back to his old teasing self. "Can I come meet her?"

Rei just tutted and started to walk away. Nagisa followed, leaping up and draping himself over Rei's shoulder. Excitement and love and terror and anger jolted through Rei all at once, and he shook Nagisa off so hard that the other boy's back hit the wall.

"Stop hanging all over me! I hate it! Just how much more do you want to mess up my life?!"

People were probably watching, probably already whispering to each other. Rei couldn't see or hear them — all he was aware of was his own ragged breaths and the look in Nagisa's eyes in the instant before Rei turned wordlessly and walked away.

After that, Nagisa was the one doing the avoiding.

Rei's grades didn't improve, and his butterfly stroke got sloppier and slower until Makoto had to take him aside and give him a talk about teamwork and supporting each other that basically amounted to: If you don't start improving, we won't be able to compete as a team.

There were no more jolts or surprise epiphanies. In that sense, Rei had finally got what he wanted. But the memory of Nagisa's face in that moment before he turned away, and the incredible tension of the couple hours a day they had to swim in the same pool together… it settled in Rei's heart and gnawed away at it until simply coming into school became almost unbearable.

Nearly a week later, and Rei couldn't even think straight. He felt sick to his stomach with guilt. It was a hot, cloying sensation crawling through his head, spreading through his chest. It was… it was…

The world began to spin. Rei felt himself falling.

No Theory

As it turned out, the symptoms of guilt were very similar to the symptoms of a cold, and Rei was suffering from both.

A helpful classmate had brought him to the infirmary, where he was tucked into a bed to rest. After fussing over him with a thermometer and putting a cooling pack on his forehead, the nurse had made him promise to stay in bed while she left to attend to something elsewhere in the school.

Even though it meant missing swimming practice, Rei could only agree. He felt better, probably even well enough for some gentle laps of the pool, but he didn't want to see any of his friends right now. Shame coiled through him, and he drew his legs up to his chest and curled in on himself. He'd never felt so miserable. And it was entirely his own fault.

After dozing for a while, Rei woke to see his friends walking through the door, looking awkward and concerned. One glance to the clock told Rei that they had ended practice early to come see him.

"How are you feeling?" Gou asked.

"I'm sor—" Rei began.

"Don't feel bad for missing practice." Makoto smiled gently. "I should be apologizing for not noticing you were feeling sick."

"Your form has been terrible lately," Haruka said.

"Haru!" Makoto chided.

But Rei didn't mind, because he understood that it was meant as an expression of understanding, rather than criticism.

Nagisa hovered slightly behind everyone else, and didn't speak to Rei directly. He didn't look all that well, either. He looked like he'd been missing sleep. Rei's heart shuddered painfully.

After their well-wishing was done, everyone turned to leave Rei to recover in peace. Rei wished he was brave enough to call Nagisa back, to speak to him.

But Nagisa stopped at the door anyway, almost as if he had heard the words Rei wanted to say without them ever being spoken. He took a couple of hesitant steps back into the room, closing the door behind him.

Rei opened his mouth, but still nothing would come. No apology or explanation or even just simple thanks for visiting. Nagisa didn't seem to notice Rei's struggle — he had his own purpose.

Suddenly bowing low, he balled his fists at his side and said, "I'm very sorry!"

Now Rei couldn't talk for a different reason. Shock had stolen his voice.

Nagisa continued, "I know that I'm at least partly to blame for all of this."

Rei gaped. Nagisa blamed himself for Rei catching a cold?

"I've made you feel so stressed. It's my fault."

"No, Nagisa—"

"It's okay, Rei-chan. I understand." Nagisa came up from the bow, but kept his eyes low. "I really never meant for you to find out how I felt. I knew it would only be a burden."

Rei didn't know what to say. He didn't even know what he was hearing.

Nagisa's face and voice were tense with false cheer. "But since it's too late anyway, I'd just like to say one thing."

Too late? The words echoed in Rei's head.

Bowing low once again, Nagisa said, "Rei-chan, I love you."

Then, with a deep breath, he straightened up and showed Rei a different smile. It wasn't as bright as his usual one, but definitely more genuine than the fake one from before. It was beautiful, but tinged with sadness. Rei hated it.

"I'm glad I got to say it." Nagisa sighed shakily. "With this, I can give up on you, Rei-chan. So things can go back to the way they were. Please… please don't quit the club."

After several long moment with no response, Nagisa turned to leave.

Rei leapt out of bed and ran after him, grabbing him by the wrist and spinning him back around.

"I love you too." It came out like an accusation.

Nagisa blinked. Rei took in a shuddering breath and tried again.

"I love you, Nagisa." He clenched his fists and couldn't bring himself to make eye contact. "But I'm scared, and confused, and I'm sorry. I'm such a coward that I said something terrible to you, but I think I really love you. I don't want you to give up on me."

It was Nagisa's turn to stand speechless. Rei forced himself to look up, into those wide, heartbreaking eyes.

"Please… please don't give up," Rei said, trembling.

Nagisa stared for a moment longer, then smiled so bright it was blinding. He closed the distance between them in one step, and rose onto his tiptoes to press his mouth to Rei's.

It all came surging back at once. Rei's entire body jolted with uncountable painfully happy feelings, and he kissed Nagisa just like he'd dreamed of doing.

Before either of them knew it, they were back to the bed, Rei pressed down into the mattress, Nagisa kneeling over him, grazing tantalizingly over his lap as they swapped deeper and deeper kisses.

Rei finally drew his mouth away to say, "You're going to catch my cold."

"That's fine," Nagisa answered, pressing sweet little kisses onto Rei's chin, his cheek, his neck. "Give me everything, Rei-chan."

Almost without thinking, Rei's fingers found their way down Nagisa's body, nervously slipping just under the waistband of his pants to—

The door slid open and suddenly Nagisa was standing a good three steps away from the bed, looking like a boy trying far too hard to appear innocent.

"I hope you've been resting, Ryugazaki-kun," the school nurse said as she stepped back into the room.

"Y-yes." Rei gulped.

And this was what made Nagisa so scary. He made Rei forget his sense — to the point that Rei was making out with him in school, in the infirmary, where anyone could and was likely to walk in, and he hadn't even thought about the repercussions until this very moment. Nagisa really messed him up, without even trying.

"I'm feeling much better," Rei said, desperate to leave as soon as possible.

The nurse looked dubious. Nagisa chimed in.

"Don't worry. I'll get him into bed."

The effect was instantaneous. Rei blushed bright red. So did Nagisa.

"Ah, no! I-I mean, I'll make sure he rests. Through any means necessary." A beat. "Ah! I mean—!"

Unable to bear anymore, Rei stepped in. "Nagisa will look after me."

Satisfied, or maybe just tired of the two of them, the nurse waved them out.

They walked together to the station. Obviously, they couldn't do anything as blatant as holding hands. But they walked close enough that their fingers would brush together every now and again.

Nagisa was talking happily, about anything and everything, about all the things he couldn't say while Rei had been trying to cut him out of his life. As Nagisa went on and on, Rei found himself thinking how much he'd missed this.

The thought slowed him down, and Nagisa noticed immediately.

"Rei-chan, are you okay?"

He was still smiling, but Rei could see the serious sharpness of his eyes. More than ever before, Rei felt aware of the quiet, hidden strength of Nagisa. And suddenly he knew: When Rei was scared or drowning in his own suffocating logic, Nagisa would be there every time, with those same sharp, kind eyes, asking if he was okay.

"Yes," Rei answered, and meant it.

Nagisa will look after me, he'd said. And he knew that it was true.