Prologue
Katsuo never imagined that a simple stormy night would change his life forever. At twenty years old, he was an ordinary young man whose mundane worries didn't go beyond deciding his next step in college. But that night, a lightning bolt not only illuminated his room — it seemed to tear through the very fabric of reality.
When the light dissipated, Katsuo realized he was no longer in his room. The surroundings felt like something out of a dream — or a nightmare. He was in an endless corridor with stone walls that pulsed as if alive, forming patterns that defied logic. An ethereal light bathed the space, though no visible source could be found. It was as if the entire place was wrapped in an ancient veil of mystery, where reality itself felt malleable.
A few meters ahead, a single door broke the monotony of the corridor. It seemed to call to him, like a promise of salvation... or a disguised trap. Its surface was etched with finely carved runes, faintly glowing and pulsing like an anxious heartbeat.
Before Katsuo could take a step, a high-pitched sound echoed through the corridor. Claws scraped against stone like nails on a chalkboard. He froze, his heart pounding in his chest, and slowly turned. What he saw stole his breath: a beastly creature with glowing red eyes full of ravenous hunger and teeth so sharp they seemed capable of crushing bones with a single bite. Its claws struck the ground with relentless rhythm, closing the distance between them.
Panic paralyzed him for a moment. But then, as if fate itself had intervened, the door opened. A figure emerged, a girl with eyes that carried as much mystery as the corridor itself. Without saying a word, she extended her hand to Katsuo, pulling him inside the apartment and shutting the door behind them, leaving the beast outside with a frustrated roar.
Inside the apartment, the atmosphere was confining, as if the entire world was limited to that one space. The girl, who introduced herself as Kira, explained that this was her world — the only one she lived in, but not the only one that existed.
The door Kira had opened was a portal to this corridor, a space between worlds. It was not a world in itself but a link between them. The corridor was a place of wonders and dangers, with mind-bending labyrinths, hot springs that could heal or drive one mad, caves brimming with ancient secrets, and monsters like the one Katsuo had just escaped.
Katsuo's journey was just beginning, alongside Kira, with the unknown stretching out beyond the door, calling him to the threshold of infinity.
Chapter 1 - The Threshold of Infinity
The Encounter
Katsuo's heart was still pounding as he looked around Kira's apartment. Despite the recent danger, the place emanated a strange sense of safety, like an island in the middle of a stormy sea. The decor was cozy, balancing between modern and homely, but the true nature of this place remained a mystery to him.
"Are you alright?" Kira's voice was low, almost hesitant, but carried genuine concern. Her eyes seemed to scan him, searching for signs of injury or worse.
It took Katsuo a few seconds to respond, his mind still piecing together what had just happened. "I... I think so." He swallowed hard, glancing back at the door. "But... what was that? That monster?"
Kira sighed, her expression a mix of pity and exhaustion. "One of the many horrors of the corridor. They aren't supposed to be here... but ever since she arrived, nothing has been safe."
Katsuo frowned. "She? Who is she?"
Kira hesitated, as if the words were hard to say. "The Evil Kira. At least, that's what I and... other Kiras call her. She's different. Dangerous. She's the one who brought the monsters into the corridor."
A chill ran down Katsuo's spine. "Other Kiras? How many are there?"
Kira averted her gaze, her fingers playing with the hem of her shirt. "Countless," she replied with a slight shrug, as if the answer had long since lost its impact on her. "Some are very similar. Others are so different you'd hardly recognize them."
He looked at the door, feeling a mix of fear and fascination. "And that door... it always leads to the corridor?"
"Yes, but the corridor is... unpredictable. It leads to different worlds every time. You have to be prepared for what you might find."
Katsuo sat on the sofa, running his hands through his hair as he tried to process everything. "So... this is your world? The apartment?"
Kira smiled, but there was something sad in her expression, an invisible weight buried in the folds of time. "It's what I can call a world. But there are others. Many others. All connected by the corridor. Each one with a version of me."
Katsuo absorbed this information in silence. Finally, he stood and walked to the window. Outside, there was no landscape — just a starry void that seemed infinite, as if the apartment floated in the cosmos. Something about it filled him with both awe and a quiet terror.
"And now?" he asked, not taking his eyes off the view. "What happens to me?"
Kira walked up to him, stopping by his side. "Now... you decide. You can stay here, safe, while we figure out how to get you back. Or... you can open that door and face the unknown."
Katsuo looked at Kira, his eyes reflecting a mix of fear and determination. He didn't know what to choose yet, but one thing was certain: his life would never be the same.
The Conflict
As Katsuo and Kira spoke, trying to understand their places in the universe, a dark mist began to form in the center of the room. The temperature seemed to drop, and the once-cozy atmosphere grew heavy with tension. Within the mist, a silhouette took shape — distinctly feminine, with contours that strongly resembled Kira's.
The figure turned to Katsuo, and a voice, identical to Kira's but possessive and menacing, echoed through the room. "I found you," the voice said, freezing Katsuo in place. "Did you think you could escape?"
Then she looked at Kira, disdain dripping from her tone. "Oh, you again?" she said, with a laugh devoid of humor. "Don't get in my way, girl. He's mine. I brought him here."
As the mist began to dissipate, her voice ended with a clear threat: "Give him back. This isn't a request."
Katsuo, still reeling from what he had just witnessed, looked at Kira, who seemed torn between fear and anger. She shook her head repeatedly, murmuring, "No, not again."
"What... what was that?" Katsuo asked, his voice trembling.
Kira took a deep breath, trying to compose herself. "That... was the Evil Kira," she explained, resigned.
Katsuo felt a shiver run down his spine. "She... she said she brought me here."
Kira nodded, worry etched on her face, her eyes reflecting an internal struggle. "She has that ability somehow. She manipulates the corridor, the worlds, and sometimes... takes people. I don't fully understand how."
He glanced at the door leading to the corridor, now an even more foreboding place. "And now? What do we do?"
Kira walked to the door, looking at it with a mix of determination and despair. "I need to protect you. But also..." she hesitated, "maybe the only way out is through her world. But it's incredibly dangerous. Or..." She turned to Katsuo, "...you could stay here with me until we find a safer solution."
Katsuo felt the weight of the decision. Staying meant safety but also abandoning his life. Going after the Evil Kira was an incalculable risk, but it might be his only chance to return home.
Kira stared at the door, lost in thought. She wanted to protect Katsuo but also knew she needed to find a way to restore his life. The fear of what the Evil Kira could do loomed over everything, making the future all the more uncertain.