Kazuki Kenmoto stood in the school gym, throwing punch after punch at the heavy bag in front of him. His light brown hair clung to his forehead, drenched in sweat, while his teal eyes remained focused on his target. He wore a dark blue tank top with the words "One Punch" written boldly in white and matching dark blue shorts. Each strike echoed faintly in the now-empty gym, his breaths coming in controlled bursts.
Suddenly, he felt a hand on his shoulder, snapping him out of his concentration. Turning around, he saw Yuto Nakamura, the captain of the boxing club and his sempai. Yuto's brown eyes gleamed with their usual calm confidence, and his natural blond hair, damp with sweat, framed his kind face. As always, his gentle smile—famous for winning over nearly every girl in school—was firmly in place.
"What's the matter, Yuto-sempai?" Kazuki asked, wiping his forehead with the back of his glove.
"As usual, you didn't hear anything while you were practicing," Yuto replied with a light chuckle. "I already called out to you twice. It's time to close the gym—the others have already left."
Kazuki glanced around and realized the gym was indeed empty except for the two of them. Reluctantly, he removed his gloves and let out a small sigh. "Sorry, Yuto-sempai. I'll get changed right away," he said before heading toward the locker room.
"Wait, I'll join you," Yuto called after him, following close behind.
Inside the locker room, the two began changing into their winter school uniforms, which consisted of a dark blue jacket, jeans of the same shade, a white shirt, and a red tie.
"Kazuki," Yuto began, breaking the silence. "Your sister should be back next week, right?"
"Yeah," Kazuki replied while fastening his tie. "Why?"
"I was thinking of throwing a party to celebrate her return. Do you know the exact day?"
Kazuki shook his head. "No, she hasn't told me yet, but I think she's coming back this weekend."
"Alright, let me know as soon as you find out," Yuto said, finishing up and heading toward the door. "Bye, Kazuki. See you at training on Monday."
"See you, Yuto-sempai," Kazuki replied as Yuto left. A short while later, Kazuki had also finished changing and exited the gym, walking home with a calm stride.
On his way home, Kazuki couldn't stop his thoughts from drifting to his little sister, Yui. After nearly a year apart, the anticipation of her return filled him with excitement.
Kazuki and Yui had been inseparable ever since their parents had left them ten years ago. For as long as he could remember, protecting her had been his highest priority. In fact, it was the reason he'd joined the boxing club at the start of high school—to become strong enough to ensure her safety.
But everything had changed about a year ago when Yui revealed she had been offered an opportunity to study in America for a year. While Kazuki wasn't surprised—his sister was a prodigy who, despite being two years younger, was already in her first year at his school after skipping a grade—her announcement still hit him like a punch to the gut.
She wanted to go.
Kazuki had objected, of course. The idea of his precious sister living in a far-off country, beyond his ability to protect her, was unbearable. But Yui was nothing if not stubborn. No matter how much he argued, it was clear she had already made up her mind. After a long and heated discussion, Kazuki had reluctantly agreed—on the condition that she wouldn't leave her dormitory after 8 p.m. and would call him at least once a week.
Almost a year had passed since then. He hadn't seen her in all that time, and the wait had been agonizing. But finally, that long, painful separation was coming to an end. Yui would be back soon.
Lost in thought, Kazuki suddenly became aware of a figure standing motionless in the middle of the street ahead. The person wore a black sweatshirt with the hood pulled up, hiding most of their face. The zipper was undone, revealing a white T-shirt underneath, and dark gray sweatpants completed the outfit. From their build, they appeared to be about Kazuki's age, lean but not particularly intimidating.
And yet, something about them sent a chill down his spine.
Kazuki's instincts screamed at him to stay away. He adjusted his path and walked past the figure as casually as he could, hoping the person wasn't waiting for him. He held his breath as he passed, keeping his focus forward.
The stranger didn't move.
Relieved, Kazuki exhaled softly. Still, his heart raced. He couldn't explain it, but something about that person unsettled him deeply. Increasing his pace, he put as much distance between himself and the figure as possible. After a few seconds, he glanced over his shoulder to check if they were still there.
They were gone.
"Thank goodness," Kazuki muttered under his breath. He tried to brush off the unease creeping through him. "If I see them again, I'll call the police. I don't want shady people hanging around this neighborhood, especially with Yui coming back soon."
But the thought lingered. Normally, he would've confronted someone acting suspicious in his area. Yet, in that moment, every fiber of his being had told him to avoid that person.
Suddenly, a voice came from behind him.
"Hey, persona, isn't it a bit rude to ignore someone who's been waiting for you for over half an hour?"
Kazuki froze, his blood turning cold. Slowly, he turned around to see the hooded figure standing just a few feet away, their face still partially obscured.
His mind raced. "How the hell did he get behind me?! I didn't hear a single sound! There's no way my senses are that bad! "
With a nervous smile and beads of cold sweat forming on his forehead, Kazuki said, "Are you sure you've got the right person? I don't know anyone called Persona."
The stranger chuckled softly. "No, I'm quite certain you're the one I've been waiting for, Kazuki Kenmoto-kun. And just to clarify, persona is how you say 'person' in Italian."
Kazuki's forced smile faltered, replaced by a serious expression. His hands balled into fists at his sides.
"So, what do you want?" Kazuki asked, his voice sharp, his body tensed in preparation for a fight.
"There is someone who wants to meet you. Come with me," the hooded figure replied.
"What if I refuse?"
"Of course, you're free to do so," the stranger said, a hint of mockery slipping into his voice. "But I've been ordered by that bastard to bring you to him. If you won't come willingly, I'll be forced to use... less pleasant methods."
"I saw that coming!" Kazuki snapped as he launched a punch at the stranger's face. It was fast and well-aimed, honed by years of boxing training, but the hooded figure dodged it effortlessly with a slight tilt of his head.
"Sorry," the stranger said casually, as if Kazuki's attack had been nothing more than a light breeze. "Normally, I'd have more fun playing with you, but that bastard keeps nagging me to hurry. So let's just end this here."
Before Kazuki could react, a sharp, stabbing pain erupted in his stomach. It was so sudden and overwhelming that his legs gave out beneath him, and his vision blurred before everything went black.
When Kazuki's eyes fluttered open, he found himself strapped to a chair in a place that defied all logic. The "room," if it could be called that, seemed suspended in an endless starry sky. There were no walls, no floor—only the illusion of infinite space.
Next to him stood the hooded figure who had brought him here, but it was the man in front of him who commanded his full attention.
The man was imposing, with long white hair flowing down his back and a thick beard of the same color. His piercing red eyes seemed to look straight into Kazuki's soul. He wore a long midnight-blue robe adorned with golden ornaments that shimmered faintly, and in his right hand, he held a black scepter. Encased within the scepter's head was what appeared to be a miniature universe—a glowing bubble filled with swirling galaxies, surrounded by smaller orbs that looked like tennis balls, each containing its own tiny universe.
Kazuki's heart pounded in his chest as he struggled against the restraints. "Where am I?! Why did you bring me here?!" he demanded, his voice laced with both fear and anger.
The man's lips curled into a smile—calm, but maddeningly arrogant. "Welcome, Kazuki," he said in a deep, resonant voice. "You are outside of your universe, in my room, suspended in the void of non-existence. I brought you here because you have been chosen by me to... entertain me."
"Entertain you?" Kazuki spat, his anger bubbling to the surface. "I will never be your jester, old man! Stop talking nonsense and tell me where I really am!"
"How rude," the man said with a chuckle, unfazed by Kazuki's outburst. "I've already answered your questions, but I understand your disbelief. After all, you come from a universe where concepts like magic and dimensional travel don't exist. I assure you, though, you really are outside of your universe. But I suppose my words alone won't convince you."
With a soft tap of his scepter against the invisible ground, the man summoned a portal. It opened with a shimmer of light, revealing a familiar sight on the other side.
"My... bedroom?!" Kazuki exclaimed, staring in disbelief.
"That's right," the man confirmed, his smile widening. "I've created a portal that connects this room with your bedroom. Is that proof enough for you?"
Kazuki's breath hitched. The sight of his room—its untidy bed, the cluttered desk, even the faint scent of his unwashed laundry—shattered any lingering belief that this was some elaborate trick. Reality itself had bent in ways he couldn't deny.
After a deep, reluctant sigh, Kazuki said, "Fine, I believe you. But I still don't understand. What do you mean by 'outside my universe'? Are you saying I'm in another universe now?"
The man's grin grew even more infuriating. "Not exactly," he said, tilting his head slightly. "This room isn't part of any universe. It exists outside of all universes and multiverses. It's a space I created for myself. But don't worry—you'll soon have the chance to visit plenty of other universes."
Kazuki frowned, his unease deepening. "What?! I don't want to visit other universes! I just want to go home!"
"Ah, that's unfortunate," the man said with mock regret. "Because from this moment on, your job will be to travel to different universes and complete the missions I assign to you."
Before Kazuki could protest, the man raised his scepter. A tiny spark of blue light emerged from its tip and shot directly into Kazuki's chest. He flinched, expecting pain, but felt nothing. Suddenly, a massive portal opened beneath Kazuki's chair, its swirling depths pulling him and Enea in.
"What did you just do?!" Kazuki shouted, struggling against the ropes binding him to the chair.
The man ignored him completely and turned his attention to the hooded figure beside him. "Enea, I'm leaving the rest of the explanation to you. I've already sent all the necessary information directly to your mind."
The hooded boy—Enea—sighed heavily. "Why me? You know I'm terrible at explaining things," he muttered under his breath.
The man offered no response, his gaze unwavering. It was clear he wasn't going to entertain Enea's complaints.
Enea grumbled but relented. "Fine, fine. I don't really have a choice, do I?"
By this point, the portal beneath Kazuki's chair had begun to expand, pulling him in with an invisible force. He thrashed and yelled, "What the hell is happening?! Let me go!"
Neither man responded. The last thing Kazuki saw before being swallowed by the portal was Enea sighing and the man's infuriatingly serene expression.
With a final pull, Kazuki's vision went dark.