"What is your conclusion, doctor?" a woman prodded anxiously as she clutched two small identical children to her sides. The psychologist flicked through the papers that he had assembled in a folder, shaking his head in minute confusion. It was a case even he did not fully understand, but had thoroughly scrutinized over many weeks of interviewing and examining the children.
"I'm afraid what you have is not a case of telepathy," he began with unease. Looking up from his papers at the two young children, he pursed his lips. Did they already know? How could they not?
"Please continue, doctor," the woman urged, her voice quivering like fragile glass. He was sure their foreign condition had no bad implications, but as it was the first time he had ever seen such a thing, he could not be sure.
"Nor are they twins," he said carefully, so as not to startle the woman. "Madam, they are the same person, but opposites. My conclusion is that your daughter was the original child, and that your son was created at birth. As a consequence of his late formation, your body could not create an entirely different person. So her body prototyped the exact opposite of your daughter into another person, and birthed the two of them. Unfortunately," the doctor paused nervously, "as your son is the opposite of your daughter, he is…a vampire."
The woman gasped and peered down at her son, who clutched onto her arm. He eyed the doctor with something akin to remorse, and slowly stood.
"You two know my secret now. We cannot have that."
The two siblings stood awkwardly before the headmaster, clutching each other's hands as the man's cool eyes scrutinized them. Kaien Cross was generally a benevolent man, but his instincts cautioned him about these two. Nevertheless, he could not turn them away, orphaned as they were. Hunter twins were a rare phenomenon, and he was not about to let them disappear from his sight once more. He cleared his throat and fixed his fists into a ball beneath his chin, and began to speak.
"I will allow you to attend my school on one condition," he said firmly. "You will join the Night Class. I think it's about time we positioned some hunters – twins at that – directly amongst the vampires to keep them at bay. We've had some trouble as of late…" he trailed off. Standing, he rounded the desk and came before the two 'twins', towering over even their tall statures.
"Thank you very much, sir," the boy said and bowed gallantly. His mother had taught him about Kaien Cross, the mother he had killed. The girl smiled as well and followed her brother's actions.
"Tell me your names," Kaien said, dismissing their unexpected formality. Clearly, whoever their parents were, they knew of his reputation as the most powerful hunter in history.
"I am Kuro," said the boy, "and this is my sister, Shiro."
The headmaster pondered their names briefly, acknowledging the obvious link between the two. Black and white: yin and yang, perhaps? He smiled dismissively and gestured to the door.
"If you'll wait outside, I'll have a word with my son and then you can be on your way," he said. The two siblings smiled back, and for a moment, they looked identical to the headmaster. If it weren't for the difference in hair length, he might have thought them the same person. He watched speculatively as they left and Zero was ushered in. There was definitely something odd about the two, and he intended to find out what it was as soon as he could.
"Zero," he said. The teen huffed in response and glared at him. "Watch those two carefully. I have a bad feeling about this."