Author's Note: Content note for brief mentions of past bullying, minor gender issues (since one of Sensui's personalities is female), and internalized homophobia. Generally, severe black-and-white thinking; Shinobu Sensui was not mentally healthy before his full-fledged breakdown.

Life was clear and clean.

Shinobu had never understood why people seemed to have trouble with that. It had always been simple for him. At the very beginning, it had been a matter of bare survival: in order to see the next morning, he needed to fight the things that came after him. If he died, that was bad. If they died, that was good.

Life had never grown more complex. He'd just understood it better. The things that went after him were demons. He was a human. He must have been given these powers so he could also protect the humans who were pursued by demons, but couldn't protect themselves.

The world broadened, and then broadened again when he was approached by Koenma to become a Spirit Detective. Thus he learned how to strengthen his powers so he could combat more demons and protect more humans. It was good. That was his purpose. He killed so that others could live. He trained so that others could relax. He grew strong so that others could be weak.

That was why he had been permitted to exist.

As a further test, he had been sent something that at first seemed more complicated: a demon who seemed human-like. He'd spared Itsuki because he'd been a petty criminal, so he really wasn't very bad, but mostly because they watched the same TV show. He hadn't realized demons had enough humanity to enjoy something like TV shows. That had bothered him.

Life had settled back into a simple pattern after a while of actually knowing Itsuki, however. The yaminade looked human and sounded like a human and sometimes acted like a human, but he wasn't. There was something missing inside him.

Itsuki had laughed when Shinobu had told him that. "Oh, sweet Shinobu," he had purred, his voice doing something strange to the Spirit Detective – probably aided by his demonic powers. Never mind that Itsuki had never admitted to having any power involving his voice – of course a demon would hold something back. "Do you really believe that's true of all humans?"

Of course it was. Humans only did bad things because they were misguided, or maybe because they'd suffered some deep trauma that left them damaged and unable to act like a normal human. Demons only did good things because it served some bigger scheme or got them something they wanted. He'd explained that to Itsuki so the demon knew he wouldn't be fooled, and the yamniade had only shaken his head.

"Viewing only your own kind as 'real', and all others as animals possessed only of bestial cunning, is such a demonic trait," Itsuki had murmured, draping his arm across Shinobu's shoulders. "Oh, my dear Spirit Detective. Are you sure you weren't born into the wrong body?"

The question made him uncomfortable in ways Itsuki likely didn't know about, because sometimes he wondered what it would be like to be a girl, and his body… didn't seem right. But that was only every now and then, and mostly he was happy to be a boy and proud of his strong body. It was probably something everyone felt and just didn't mention because it was awkward. So he averted his eyes, and his cheeks burned when Itsuki laughed at him.

And it was laughing at him. Itsuki told him he really didn't mean it that way, and he was just chuckling because shyness, in such a powerful warrior, was endearing. But Shinobu knew it was laughing at him, because that was what all the children had done on the playground, and the world remained as simple as it had always been. Weird Sensui. Freaky Sensui. Crazy Sensui. He swats at things that aren't there! He's always hearing voices! I bet he's a schizo! Stay away from stupid Sensui!

He forgave them, because they didn't know better and it was his duty to protect them all. It wasn't their fault they couldn't see what he did. But he knew that people laughed at him.

He told Itsuki that, because he had worked through all this himself years ago and he didn't fear anyone using it against him, and the demon had only looked at him in a strange way. On a human, it might have been pity, but demons were pitiless. "Oh, Shinobu," he said, stroking his cheek. "If anyone were to hurt you like that again, I would break them myself."

Shinobu didn't know what he was talking about, because it didn't hurt him. That was a long time ago and he knew it wasn't the children's fault anyway. And he knew the way he felt when Itsuki said that, like someone cared about him, was just a demonic trick. He didn't need to be cared about, because he was a warrior for justice and comfort was just for people who weren't strong enough to stop themselves from getting hurt.

He'd tried to explain that to Itsuki, so the demon would stop trying to fool him, but Itsuki had just repeated that nonsense about his attitudes being so demonic and got all weird, petting him and rubbing himself up against him, and so Shinobu had dropped the subject. It was clear Itsuki wanted to persuade him his thoughts were bad and wrong so he would become bad and wrong like the yaminade, and he wasn't going to fall for it.

He also understood the other kind of way Itsuki tried to corrupt him. Contrary to what people sometimes thought, Shinobu wasn't ignorant of sex. He'd read about the mechanics in books and found it off-putting, which hadn't bothered him; clearly he'd been shaped to be a hero free of the need for a lover and family, so that he could give his all to everyone. It had been comforting, really, since he'd started to worry after hitting puberty that he might want a family and be tempted away from his duties. Fortunately the world was simple, and so he'd been silly to be concerned in the first place.

So, because demons were inherently evil, of course Itsuki wanted to tempt him away from that. Really, Shinobu was relieved the demon was male. If he'd been female and used his… her… demonic wiles to arouse him, Shinobu might have actually been confused and fallen for it. But, because he was male, Shinobu understood the urges Itsuki made him feel were unnatural and needed to be ignored. Yes, he'd gotten aroused by male bodies before, but he'd pushed that aside as a silly involuntary reaction because it obviously went against nature, just as he pushed away his own agony when he was injured because it didn't help, and pushed away any feeling of loneliness or unhappiness because it interfered with his duties. Humans, as he explained patiently to Itsuki, were capable of overcoming their involuntary reactions. It was part of their innate goodness. With time and willpower, they could learn to quench all their bad and inconvenient feelings, and attain true oneness with what they knew to be right.

He'd really felt sorry for Itsuki. The demon didn't understand what he was saying; he'd only looked at Shinobu with heartfelt pity, as though he were a crippled puppy. Or something like heartfelt pity. Since demons didn't feel things like pity or mercy or love, he was probably just copying something he'd seen on TV. "Shinobu," he'd said, "your life has been incredibly difficult. You should be proud of your survival; it would have killed many lesser demons. But the one thing we who survive learn in the Demon World is that all things, in time, fall apart. Even the mightiest demons one day meet challengers who overtake them. Though they stand invincible for hundreds of years, the time comes when they are killed, and it is as though they never were. So it will be with your battle with your emotions. Someday, the time will come that some great strain proves too much for you, and everything you have been suppressing, all your life, will burst free and drown you."

"And you'll be waiting for that, I'm sure," Shinobu had chuckled.

Itsuki had not. "I will."

He felt no hatred for Itsuki. The demon had no choice in being evil. It was his nature, as being human was Shinobu's. And at least he didn't go around killing people; his kind of evil was attempting to bring corruption into others' hearts, and so Shinobu could stop his evil by soaking it all up, since he himself was incorruptible.

Maybe that was why Itsuki had been allowed to come into existence: so Shinobu could be tested by real, serious temptation and prove that he would not succumb to it. Shinobu felt fond of him for that. It was good to be around another living being with a real purpose to exist, even if Itsuki's was expressed by his being evil.

Understanding that calmed him down. Life was so simple. Other humans only thought it was complex because they were confused, and that confusion was the source of all their suffering in life. Once one saw clearly, as he did, all that pain and conflict could be silenced, and one could go on contentedly living one's life, no matter what trials were placed in one's way.

So he looked forward to his latest assignment with a steady gaze and a pure heart. Something about the… what was it? Ah, yes, the Black Black Club. Even Itsuki's eyes had widened at that name, and he'd whistled softly under his breath and murmured, "Oh my," but Shinobu didn't really understand why. Koenma himself had been very cautious about describing the assignment, as though he were treading over broken glass, but Shinobu hadn't understood that either. So there were humans doing bad things to demons, even though the demons hadn't done bad enough things to deserve that, and he'd have to stop them. He'd been able to smile at Koenma and tell him it really wasn't necessary to treat him like fine china, and at last his boss had relaxed and murmured that maybe he could handle it after all.

He wasn't a child. He understood. The humans must have been misguided. He would go and stop them from doing the bad things, and then explain to them why it had been wrong. Perhaps demons had harmed their families, and so they had decided all demons deserved punishment, regardless of whether they'd done significant evil yet or not –

Itsuki had rapidly shaken his head when he'd explained that after their meeting with Koenma, looking frightened (for him?), and told him, "No, Shinobu, you truly do not understand." But of course he did. Humans would never hurt demons just because they liked their pain. That was, as Itsuki would say, a demonic trait. Only demons did that. Just as they had done to him, when he was very small, and desisted only when he had begun to hurt them back.

Itsuki had only grown subdued and quietly sworn to him that, however he reacted to what he truly found in the bowels of the Black Black Club, he would remain by his side afterwards. His lack of flamboyance had disconcerted Shinobu, but it had to be a trick. Itsuki knew perfectly well that he could handle whatever physical opposition they threw at him, and, having torn foes asunder with his spiritual energy almost from infancy, he'd left mere squeamishness behind long ago.

Whatever he did find down there couldn't prove too disturbing, anyway. After all, life was clear and clean, and humans were good and demons were bad.

That was all there was to it.