Set before the manga, after the events in Hijiri's flashback. I think it all fits with canon, but let me know if I've missed any details.

I wrote this because I thought some important closure/character development was missing after the whole Satsuki affair. I think this, or something like it, must have happened for them to be where they are now.

Their acquaintance began quite dramatically. After that sort of introduction, Hijiri had two choices about how to act – he could either avoid or cling to Toru. Given his insecurities, his need for a purpose, it was no surprise that Hijiri chose the latter option, and took to almost constantly following the Iris Zero around.

Toru didn't much like that at first, of course, but despite his sharp words he was a rather lonely kid and in need of a friend. He ended up giving in to Hijiri's presence relatively quickly ("Well, it seems I won't be able to get rid of you," he sighed with a barely noticeable smile), and their friendship was built off a strong foundation of trust, with almost unhealthily strong pillars of need. In fact, Hijiri needed Toru so much at first, and Toru was his savior in so many ways, that had Hijiri been a girl, he'd probably have fallen in love with Toru before very long. Instead, he'd just been able to relax in Toru's presence, to discover his own personality in ways he'd never done before.

For the first time in years, Hijiri was truly happy. He realized that his feelings for Satsuki had never been as real as this friendship – not because she was unworthy, or because he hadn't honestly liked her – but because at that time, Hijiri had still been searching for a purpose, a reason he was alive. Now, he thought more along the lines that he was alive and the reasons didn't matter. As long as he existed, he might as well go ahead and enjoy himself, Hijiri thought, and found himself transforming into quite the cheerful and whimsical person as a result. Toru didn't act the least bit surprised at his new friend's transformation, and Hijiri's trust in Toru's mind was complete enough that he was convinced Toru had suspected things would turn out this way all along.

Life was good – life was real in a way it hadn't been since his grandfather's death. Hijiri treasured it, kept his pocketknife tucked away in his desk drawer and never took it out, and spent as much time as possible with the Iris Zero who had made it all possible.

Then Toru's family went on a two-week vacation to visit relatives out of town, and everything collapsed.

The destruction began simply enough; Hijiri wasted his day reading manga and then, in late afternoon, decided to try a little studying. He opened his desk drawer to retrieve his calculator, and his eyes fell on the pocketknife rattling about in the drawer. And though Hijiri had faced this sight for over a month now without any reaction or need to do anything with the knife – this time was different. He saw the blade, folded up inside its casing, and he thought of black butterflies, and he thought of Toru.

And he thought Toru could be in danger right now, could already be gathering butterflies from something as simple as walking down the wrong alley in an unfamiliar city. Toru could be swarming with black butterflies by now, so many that Hijiri wouldn't even be able to see his body beneath them – and he wouldn't know, wouldn't be able to protect himself. Hijiri's Iris only worked with people physically in front of him; even if Toru sent him a photo every day that wouldn't make a difference. Hijiri could be losing Toru even right this instant and he was absolutely unable to save his friend from here.

Hijiri was useless, suddenly convinced Toru would die and leave him alone and worse than ever. Terrified, he fumbled for his phone and sent a desperate text message demanding Toru return immediately. The reply was quick and simple.

[No way.]

Fingers shaking so badly he could barely type, Hijiri asked where they were, if he could join them, which train to take. He waited for the reply, this time with a grip so tight round his phone that his knuckles clenched white, and minutes ticked by with agonizing sluggishness.

Toru never answered.

Hijiri flung down his phone and snatched up his pocketknife in one motion, terrified beyond all thought and reason, and yanked up his sleeve to expose his wrist. He flicked open the blade and balanced it over his skin, just as he'd done so many times before. Trembling uncontrollably, Hijiri pressed the blade in…

He stopped, just as the pressure became enough for a thin line of blood to spread under the shine of the knife. He stared at his wrist in such shock that his mind went completely blank and he didn't know whether he felt happy or horrified.

Fluttering gently against his leaking veins… was a black butterfly.

-xxx-

Hijiri had never seen a butterfly near himself before. He'd never even thought about it. Lots of people couldn't use their Iris on themselves, so a lack of black butterflies around himself, even when he had cut himself so much more often before, had never seemed off to Hijiri.

But now, the sight of it was shocking, sickening. Did this mean that all those other times he'd cut himself, he was never even in the slightest danger of dying? His thoughts about suicide were never real? He had been so serious about it then, or he thought he had, anyway – could it be that he'd been deluding himself all along? Well, in the end he was always too cowardly to go through with it, no matter what he thought.

But he had thought about it, rehearsed it in his mind. This time, suicide hadn't crossed his thoughts at all. He'd felt terrified, careless, in a frenzied panic for Toru's life – not depressed about his own.

And yet… the butterfly was still there. Even after Hijiri slammed the knife back into the drawer and bandaged his wrist, it didn't fly away. It stayed, wings flitting agonizingly against his skin, not quite touching, and no matter how he tried to brush it away, it just barely avoided his fingers and came back.

Hijiri felt his whole body trembling. He couldn't make himself look away. When his mother knocked on his door to announce it was time for dinner, he jumped all the way out of his seat.

What did this mean?

He skipped dinner, claiming to feel ill – not really a lie, as his stomach was churning and his heart racing. Hijiri was suddenly terrified of the world. What if he left his room, and more butterflies came? What if he stayed at his desk, and more butterflies came? What if he picked up the knife – what if he picked up a pen? What if he picked up nothing at all?

What was going to kill him?

Hijiri didn't know. All he knew was that it was likely, getting likelier, that he was going to die soon, and Toru wasn't there to save him.

–Toru!

[You need to come back. You need to come back. Toru, I need you to come back.]

[Toru. I've got one. There's a black butterfly on me. I can't make it go away!]

[Answer me! Look at your phone already!]

[Please, Toru… Help me…]

Hijiri sent text after panicked text, called dozens of times, but although the phone rang and rang, not once did Toru pick up. The text messages went through but not a single response came. Hijiri was alone, helpless, no one was coming to save him because no one would even understand what was wrong, he was going to die and where was Toru?

It took him until three in the morning to fall asleep, and he flinched from nightmares the entire time, tightly gripping his bandaged wrist.

-xxx-

The next week was a gradual hell on earth for Hijiri. He withdrew into himself, became a paranoid wreck, and on the eighth day of Toru's trip with no reply, he finally realized that none was coming.

Toru was not going to save him. Toru was hours away, and his phone might even be off for all Hijiri knew; if it was on, he certainly wasn't checking it.

Or maybe he was, but he just didn't care.

Hijiri tried to shake that thought out of his head, but it was so difficult to think positively, not when the single butterfly on his wrist had already turned into nine, surrounding him.

They never touched him, at least, but that also meant he was never sure where they all were. Hijiri was lucky it was summer vacation; it meant he could get away with sitting in front of the mirror in his room all day, peering at his reflection in search of black wings.

They just kept appearing. Nine in eight days soon turned into twenty butterflies in eleven days. Toru would be back in just three days, Hijiri chanted to himself. Just three days. Just three days. Just three days until Toru came home, and everything would be fine then, he'd fix it somehow, he had to because Hijiri didn't want to die–

And then it hit him. The air Hijiri was breathing suddenly tasted entirely different. He did not want to die. He wanted to stay alive. And though this shouldn't be a revelation anymore, not after Toru, somehow it still was, because 'enjoying his life as long as he existed' was so very different from 'wanting desperately to keep existing'.

What if Toru couldn't save him this time? As impressed by his friend as he was, Hijiri knew that no one was infallible. Toru's abilities lay in his discerning intellect, not in miracle-working. Even if he did still care (he did, there had to be a reason for this, he lost his phone or something, Hijiri had to believe that), it was impossible to be sure that he would be able to save Hijiri.

No. No. He couldn't just sit back and rely on his friend. He had to do something. Anything.

But it was like Satsuki all over again. The fear was back, tenfold. What if his actions were what lead to his death? He hadn't left his house at all since he'd seen the first butterfly. What if going outside killed him? What if staying in killed him? He didn't know. He had no idea what to do.

But he had to do something.

So Hijiri went outside.

-xxx-

He barely managed to make it to the park near his home before collapsing to a bench, shivering uncontrollably. After several minutes of just sitting there, trying to fight away the nausea and fear he felt, Hijiri opened his eyes and started counting.

Twenty-eight.

Twenty-eight. A five-minute walk had added eight butterflies. God. God, he should have stayed home. He shouldn't have done this, he should've just waited for Toru, oh god he was dying. What should he do? What could he possibly do?

Right in front of his eyes, another butterfly popped into existence. It was just there suddenly, fluttering gently before his nose. His skin crawled in disgust, but Hijiri didn't jump back. There was no point, he knew that by now; he couldn't touch them.

He couldn't stop them.

The thought felt right, suddenly. Horrible, but true. Of course he couldn't stop them. There was no point in even trying. He'd never been able to do it before. Even Satsuki – that had all been Toru's mind, he'd done nothing. He couldn't ever do anything. All he could do was watch people die.

What was the point? Hijiri slumped into himself on the bench, staring at some kids playing a game of tag over by the slide. Automatically, he scanned them for butterflies, and relaxed a little when he didn't spot any.

It wasn't like he could become a doctor and save people with lots of black butterflies. When it got really bad, he wouldn't be able to see them at all under the cloud of insects, and besides the mere thought of entering a hospital sent shivers crawling horribly up his spine. He wasn't clever enough to figure out why they might die and save them that way, either. Toru might be able to do that, but Hijiri couldn't. He wasn't even particularly good in school or at sports, and he didn't have any friends except Toru, either. He wasn't really close to his parents. He wasn't an artist or creative soul in any way; he didn't bring anything to the world that someone else couldn't do better. And there were black butterflies crawling all over his skin.

He couldn't stop them. Did he even have any right to try?

Hijiri sighed, stood up, and started walking home. He felt increasingly distant with each step he took; like he was slowly floating out of his body and merely watching its progress through the streets.

At every crosswalk he thought, maybe a car will run me over. He walked over a bridge and thought, I might fall off the edge somehow and drown. He passed a murder of crows squabbling over some trash and nearly laughed out loud: hell, maybe they'll peck me and give me a deadly illness!

It could be anything. Anything could kill him. There wasn't any point in being afraid. He might be struck by lightning, or be crushed by falling debris from a construction site, or forget to turn the stove off and burn the house down with himself in it. Someone could try to mug him and end up just stabbing him in the heart. He could just suddenly have a heart attack; it'd be unusual for someone his age, but hey, it could happen.

Hijiri laughed out loud, making a game of it. That heavy flowerpot might fall on his head, that telephone wire could break and electrocute him. That man right there might go mental and just choke him to death in the middle of the sidewalk; that police officer might accidentally shoot him when trying to save him.

His butterflies just kept increasing. Thirty, thirty-four, forty-six, they were starting to swarm. They were surrounding him, and there were too many to count now, they kept popping into existence, with every step but Hijiri didn't stop walking.

It was getting hard to see. Black wings kept fluttering in front of his face, and Hijiri thought maybe I'll be blinded by them and walk in front of a bus. What would that be, a self-fulfilling prophesy? Would that count as suicide or murder or accidental death?

He made it home safely, walked up to his bedroom without a word, and locked his door behind him. The butterflies swirled ever faster, ever closer as he went to his desk and sat down.

And suddenly he realized.

"Oh," Hijiri said. He reached into his drawer and picked up his knife, flicking it out of its case with practiced ease. A butterfly landed on its tip, antennae trembling against the metal.

Hijiri smiled, strangely calm. So this is how.

He spared a last glance to his phone; no new messages. Of course not. Toru couldn't save him from this. No one else could ever save him from this. He'd brought it on himself.

He held the knife to his wrist, and closed his eyes against the rush of black wings.

This is the end.

-xxx-

[We just got back. Can I come over?]

Hijiri stared at his phone for a long time. No matter how he looked, that was all Toru's message said. Finally, he replied.

[Sure, c'mon over.]

Ten minutes later, the doorbell rang. Hijiri went downstairs and let him in. Toru smiled widely at him, breathing heavily, his skin a little tanned from the summer sun. He looked the same as ever, otherwise.

Hijiri punched him in the face.

"YOU BASTARD," he shouted, and then punched again. Toru didn't dodge, and his knuckles smashed against his friend's cheekbone. It hurt, and Hijiri wondered if he was doing it wrong. He'd never punched someone before.

Even so, he punched Toru again. And again, and again, and just one more time, and then he yanked him close and hugged him tightly. He had tears in his eyes; they felt wet and hot and full up.

"You could've killed me," Hijiri muttered, not sure why he was hugging Toru instead of still beating him up, but unwilling to let go. "You could've been killing me and you didn't even care."

Toru pushed him away. His expression was as calm as ever, despite his cut lip and swelling eye. "No," he said thickly, then made a face and swallowed what must've been a mouthful of blood. "No, that's not true. I was really… scared for you. I didn't know if you'd make it."

Hijiri laughed hollowly. "I almost didn't. Three days ago, I –" He choked on the words.

Toru smiled shakily. "But you did. And – and if I had come home earlier – if I'd fixed this for you…"

"What?"

Toru met Hijiri's eyes steadily. "If I had, you definitely would have killed yourself. Maybe not right now, but you would have, eventually."

His words were painfully blunt; they hit like a blow. Hijiri's thoughts flashed back to three days ago – to the blade against his skin, the butterflies covering his body, the absolute dull certainty that he was simply fated to die this way and there was nothing he could do.

And then he'd realized something. He wasn't scared anymore. His fingers weren't shaking, his thoughts were calm; he could look at the black butterflies all over himself without any dread. He just wasn't scared.

There was no reason to be scared.

The butterflies weren't holding the knife; he was. The butterflies weren't going to kill him. The butterflies couldn't do a thing, and they didn't mean a thing either, not unless he let them. He could choose to make them a self-fulfilling prophecy, sure. But it would be a choice, because they were saying Hijiri was going to commit suicide and that was up to him.

He closed the knife, and put it away. And just like that – the butterflies were gone. All of them. All at once. It was amazing and completely due to his own actions and Hijiri had cried himself to sleep in pure relief.

Toru was staring at him now in a way that begged him to understand, and Hijiri grinned ruefully.

"Yeah," he said slowly, thinking it over. Imagining a future in which Toru had rescued him, and he'd never realized that he controlled his own life or even that he wanted to keep on living. A future in which he clung ever closer to Toru, depended on him for absolutely everything and grew terrified whenever they were separated. A future full of black butterflies; a future of constant, maddening fear. "Yeah, I probably would have. Might've killed you, too."

Toru flinched a little – but then he smiled a pained smile, gesturing at his face. "This doesn't count?"

Hijiri held up his hand. The knuckles were already red and swelling. "Please, I think I hurt myself more than you. C'mon, I have a really big supply of bandages in my room."

Toru laughed. It was a slightly bitter laugh, but it was genuine, and after they had bandaged themselves and found a bag of frozen peas to put over Toru's black eye, he reached out and grabbed Hijiri's hand.

He didn't say anything. Just twisted his lips a little, squeezed once, and then let go.

Hijiri felt warmth welling up inside of him, and blinked hard. His smile in return was a little wobbly. "You're a great friend to have," he said. "I bet you'll let me copy your summer vacation homework."

Toru snorted. "We don't even have the same assignments; and anyway, I was on vacation."

"Don't lie to me. I know you're done already."

"…Doesn't mean you can copy my work."

"I've got to," Hijiri said. "I need to get good grades, Toru, or how am I ever going to get into the same high school as you?"

Toru's eyes widened. Those eyes, which saw nothing and yet everything all at once, never surprised, always analyzing – they went incredibly wide for a moment. "Oh," he said softly, sounding completely taken aback. "Well, then I guess I'd better help you out."

Hijiri stared, finally realizing that he wasn't the only one benefiting from this friendship at all. Toru had taken only ten minutes to get here. He must have run all the way from the station. He'd let himself get punched. He'd probably expected Hijiri to hate him, but he'd come anyway and he'd been surprised just now.

"Yeah," he said after a minute, throwing a casual arm around his best friend's shoulders. "Guess you'd better."