It wasn't long before the class became aware of the arrival of the second transfer student. The school was abuzz with rumors about him even before he made his appearance. There had been whispers of his mysterious background and his peculiar abilities, and the students had already been on edge since Koro-Sensei's explosive entrance into their lives. They were expecting something extraordinary.
Then, as if answering their unspoken thoughts, a tremendous crash echoed through the classroom. It was as if a bomb had detonated, causing the entire wall to break open. Shards of concrete and dust flew into the air, and for a moment, the students could only gape in shock at the sight before them. Standing amidst the rubble was a boy. He was calm, unfazed, even as the remnants of the broken wall scattered around him. Without hesitation, he walked through the destruction, his presence as bold as the hole he had just created.
"I've proven myself victorious to the wall," the boy said, his voice laced with an air of authority and pride, as if destroying the very barrier between him and the world was the easiest thing in the world. The boy's arrogance was palpable, and yet, his posture was oddly relaxed, as if he were more amused than angry by the situation. He made his way through the classroom, picking out an empty seat with casual ease.
Behind him, a figure clad in stark white clothing entered. The man's appearance only added to the surreal nature of the moment. His white attire, pristine and flowing, contrasted sharply with the crumbled debris at his feet. He exuded an air of quiet authority as he spoke, introducing the boy who had just broken through their walls in such an unconventional manner.
"This is Horibe Itana," the man in white said, his voice steady, though his presence was distinctly unnerving. The students barely processed his words, still in shock over what they had just witnessed. The man's identity was a mystery, and yet his words seemed to carry weight, as if he were familiar with Koro-Sensei in some way. He had an aura that suggested power, the kind of power that could break through anything—and anyone—that stood in his way.
Koro-Sensei, ever the curious teacher, floated forward, trying to calm the students down. But even he couldn't shake off the unease that permeated the room. His attention remained fixed on Horibe, trying to make sense of the boy's unexpected entrance.
Karma, always quick with a sharp retort, broke the silence with his usual sarcastic flair. "Why aren't you wearing proper attire when it's pouring outside?" he asked, his voice dripping with mockery. It was a typical Karma move—trying to cut through the tension with humor.
But Horibe's reaction was immediate and unsettling. His sharp eyes locked onto Karma's, his gaze cold and calculating. Without missing a beat, he responded in a chillingly calm tone: "You're weak, so I won't kill you."
Then, to the horror of the students, he casually patted Karma on the head as if he were an annoying child, a mere inconvenience in his path. Karma froze, the mocking smile faltering on his lips. The students exchanged nervous glances. This was no ordinary student. There was something dangerous about him, something that felt far too familiar in its aggression.
At that moment, the air in the classroom shifted, tension crackling like static. Horibe stood up, his posture now more assertive. He locked eyes with Koro-Sensei, his lips curling into a smirk that sent a shiver down the teacher's spine.
"Brother, you are my only match," Horibe said, his voice taking on a new intensity. The words hung in the air like an echo. A deep, unsettling silence followed.
The class gasped in unison, as if they had been slapped. Everyone turned to Koro-Sensei, their gazes now filled with confusion and disbelief.
"Brother?" the students repeated in stunned unison. They looked at Koro-Sensei, who was floating in midair, his normally calm demeanor rattled for the first time since his arrival. How could this boy be Koro-Sensei's brother? He had never mentioned a sibling before, and the idea seemed impossible. Koro-Sensei was an enigma, and now, it seemed, even his past was a mystery.
Koro-Sensei, his usual jovial and carefree nature momentarily forgotten, stumbled over his words. "I… I was raised an only child!" he protested vehemently, clearly flustered by the assertion. There was no trace of recognition in his voice, only confusion. "I've never had a brother!"
But Horibe seemed undeterred. In fact, he seemed almost amused by Koro-Sensei's reaction. His eyes gleamed with excitement as he took a step forward. "Today will be the final class," he said, his tone filled with the anticipation of someone about to face a long-awaited challenge. There was no fear in his voice—only the thrill of the battle ahead.
The room fell into silence once more.
"Sensei! You had a brother?" one of the students finally asked, breaking the tension. The thought was too absurd to process. How could Koro-Sensei have a sibling? What was going on?
"No! No! No!" Koro-Sensei stammered, his voice rising in panic. "I've never had a brother! There's no way that's true!"
The next day, the classroom was in a state of nervous anticipation. Word had spread that Horibe was challenging Koro-Sensei to a battle—something that none of the students had ever dared to do before. The atmosphere was electric, with everyone unsure of what to expect. This wasn't a normal lesson—it was something much more dangerous, and Koro-Sensei seemed less certain of his victory than ever before.
As the match began, Koro-Sensei floated to the center of the room, his usual carefree smile replaced with a rare seriousness. "Anyone who steps out of this ring or harms the spectators loses," he muttered, his voice firm. He had seen many battles before, but there was something about Horibe's energy that felt like a true threat.
The students watched, their eyes wide with fear and fascination. They had seen Koro-Sensei defeat the most dangerous foes, but there was something about Horibe's confident demeanor that made them uneasy.
"Start!" Koro-Sensei called, and the battle began.
In an instant, Horibe moved like lightning. Koro-Sensei's eyes widened in surprise as Horibe's hand cut through the air with precision, severing one of Koro-Sensei's tentacles in a single motion. The students gasped. Koro-Sensei's tentacles were usually invincible—no one could damage them with such ease.
But what happened next was even more shocking. From Horibe's head, several new tentacles suddenly emerged, sprouting from his hair in an almost grotesque fashion. The tentacles lashed out with a speed that was beyond comprehension, and Koro-Sensei was momentarily caught off guard.
Koro-Sensei's face turned a deep shade of purple in frustration. "You! Where did you get those tentacles?" he demanded, unable to hide his anger
"You won't be able to ask him anything," the man in white said in a tone so final it could not be contested. With a flick of his wrist, he shot a beam of light at Koro-Sensei, paralyzing him instantly.
The light beam struck Koro-Sensei's body, causing it to stiffen as though his cells were frozen in place. He couldn't move, couldn't dodge. The energy drained from him rapidly as the beam restricted his ability to function.
"Now, your cell's velocity will be rigid, and you can't move," the man in white declared. He had anticipated this moment, prepared for Koro-Sensei's every move.
"Die, brother," Horibe said, his voice cold as he launched himself at Koro-Sensei. The intensity of the moment was palpable as Horibe swung his hand, ready to deliver the final blow.
But just as Horibe struck, Koro-Sensei executed his molting technique—a rare move that allowed him to shed his outer skin and escape a deadly blow. In the blink of an eye, Koro-Sensei was free, his molting skin creating an impenetrable barrier between him and Horibe's attack.
The room gasped in shock. The students had never seen Koro-Sensei use this technique so quickly before. The man in white merely nodded in recognition. "Molting, huh?" he muttered. "We already knew you could do that. Unfortunately for you, it consumes a lot of energy, and your physical performance has already decreased."
Koro-Sensei, now visibly weakened, growled in frustration. "This is the first time I've been cornered like this. But there are still so many questions I have for you."
Horibe grinned. "You'll never get answers."
But Koro-Sensei wasn't finished. With an impossible burst of speed, he seized Horibe in his molting skin, trapping him and preventing further attacks. Using the moment of vulnerability, Koro-Sensei attacked Horibe's tentacles with a BB knife, slicing through them one by one. Finally, in a swift motion, he hurled Horibe out of the ring, sending him crashing into the wall.
The students stood in stunned silence, unsure of what had just transpired. Koro-Sensei had won, but the cost was clear: Horibe had been a formidable opponent. Koro-Sensei's energy was visibly drained, and it was clear that this battle had pushed him to his limits.
"If you want, I can teach you," Koro-Sensei said, his voice tired but still filled with wisdom. "You need to learn from my experience if you want to win next time."
But Horibe's body began to change. His skin turned an unnatural color, and his body shook with uncontrollable energy. It was as if he were losing his mind.
Before Koro-Sensei could react, the man in white quickly intervened, knocking Horibe unconscious with a swift strike. Horibe collapsed to the ground, his body falling limp. The man in white turned to Koro-Sensei.
"I'll have to leave for now," he said, his voice carrying a finality to it.
Koro-Sensei, still shaken from the battle, tried to move but found that he couldn't. The man in white was wearing a special fabric that prevented Koro-Sensei from touching him.
And just like that, they were gone. The classroom was left in stunned silence. Horibe had come to challenge Koro-Sensei, but his true purpose remained a mystery. The questions remained unanswered. For now.
"Students," he began, his gaze drifting over the class, as if searching for the right words. "I suppose it's time for me to finally tell you the truth."
The room seemed to hold its breath, all eyes on him. Koro-Sensei paused for a moment, his eyes narrowing slightly as he collected his thoughts. For the first time in their time together, he looked vulnerable, almost… human.
"I wasn't born," he said softly, and the words hung in the air like an impossible riddle. "I was artificially created."
He looked at the students to realize none of them were shocked.
"You all knew?" he asked again, almost as if trying to confirm it.
Everyone nodded.