The moment my eyes opened, the first thing I felt was cold. The texture of concrete seeped into my cheek. The smell of exhaust fumes mixed with fried food leaking from somewhere nearby. A low beat echoed from far away. Kashiwagi Ren slowly pushed their body upright. It was a dimly lit alley. Old buildings pressed in from both sides, and when I looked up, neon light carved through the sky. Pink, blue, orange. The afterglow bled into the wet asphalt. (…Where is this?) Ren stood slowly. Black hair, slightly longer than a short cut, with a natural wave to it. A slender frame at 170 centimeters, dressed in a white shirt and black slacks. Leather shoes made a small sound against the concrete. A small piercing in the left ear caught the neon light, glinting faintly. I tried to recall my memories. Today was Wednesday. After afternoon classes ended, I was in the music room reading manuals for audio equipment. Second year of high school, studying music production. That's who I am. Kashiwagi Ren, seventeen years old. So why was I in an alley like this? I reached into my pocket to get my phone. Nothing was there. No wallet. No keys. There was only one thing. A rectangular, hard card. I took it out carefully. Small letters lined the surface. 765 PRODUCTION / PRODUCER ID An authentication chip was embedded at the edge of the card, and it felt faintly warm to the touch. My name was printed on the back. But I had no memory of it. No memory of receiving it. And I had no idea what "765 PRODUCTION" even was. (…Why do I have this?) A crease formed between my eyebrows. Ren had a tendency to become expressionless, and when confused, it showed even less on my face. But right now, my head was definitely spinning. I had no choice but to head outside. I started walking toward the alley's exit. --- The moment I stepped onto the main street, Ren stopped. It was huge. The entire wall of the building across from me was glowing. A massive LED screen. The whole building—both vertically and horizontally—had become a screen. What was displayed on it was footage of girls standing on stage. Colorful lighting, powerful music, roaring crowds. It was live footage. The building next to it had one too. And the one next to that. As far as I could see, idol live footage was playing everywhere. Day or night, it didn't matter—it just kept streaming continuously. The people passing by weren't surprised at all. They simply glanced at the footage and kept walking normally. The BGM coming from the restaurants was idol music too. A banner stood in front of a shop. It read: "Support the Resonance Live!" (Resonance Live…?) Ren stood frozen, thinking it through. This place looked modern. There were buildings, cars driving around, salarymen in suits walking past. The technology level was the same. But the entire city seemed to revolve around idols. It was as if idols were built into the urban infrastructure as naturally as any other essential service. Something was off from the world I knew. (I could search it on my phone… oh, right, I don't have one.) That's when I remembered again. No phone. No wallet. All I had was this one mysterious ID card. A cold sensation crept up from the pit of my stomach. Could I get home? And where even was this place? But at the same time, the live footage on the building wall caught Ren's eye. The stage lighting design, the camera work, the unity with the audience. Professional work. As someone studying music production, I could tell. (…I shouldn't be thinking about this right now.) Ren shook their head. I needed to focus on getting home. Walking a bit further down the main street, I spotted a sign. A nameplate reading "Shione Ward." A place name I'd never heard of. Looking at the route map beside it, I saw several wards listed: "Kagari Ward," "Minato Ward," "Yukihana Ward," and others. None of them rang a bell. (Lumière City…?) That text appeared at the top of the route map. This place was apparently called "Lumière City." Ren took a deep breath. Stay calm. Panicking wouldn't solve anything. First, I needed to organize the situation. That was my way of doing things. --- A camera mounted on a streetlight turned toward the stationary Ren. I noticed it when a dry electronic sound rang out. Looking up, a small camera attached to the streetlight was pointed directly at my face. The lens glowed. Seconds later, a white drone flew toward me. Compact body. A speaker attached to the underside, it began playing a mechanical voice as it approached. "Unidentified person detected. Based on Performance Preservation Law Article Seventeen, initiating restraint protocol." People around me stopped walking. They were looking at Ren. (Performance Preservation Law?) I quickly pulled out the ID card. I held it up toward the drone. The chip on the card reacted, a small light blinking. But the drone didn't stop. "Registered data mismatch. Continuing verification." It drew closer. (The card is real, but there's no registration?) The moment I understood that contradiction, Ren was running. My body moved before my mind could catch up. I dove into a narrow alley in Shione Ward, turned a corner, then another. Toward the shopping district. I ran through unknown streets in an unknown city, guided only by instinct. My leather shoes struck the stone pavement, the sound echoing through the narrow alley. The drone's sound grew distant. I turned another corner. This area was darker. Shops with their shutters down lined the street. No sign of people. Ren pressed their back against a wall, catching their breath. (…Did I lose it?) My chest was heaving. But I didn't make a sound. Ren quietly checked the surroundings. The drone's propeller noise was gone. Slowly, my breathing steadied. (In this city, people without ID are treated as suspicious right away. The ID card seems real, but it's not registered. What's going on?) The mysteries just kept piling up. Ren was still looking around. And then I saw it. A small stage space surrounded by shutters. --- There was a gap in the shutter. Peering inside, it was a small live venue. Or rather, "was" in the past tense was more accurate. Now it was just wreckage. An overturned speaker, severed cables, charred circuit board fragments scattered across the floor. The edge of the stage was blackened. Ren slipped a hand through the gap in the shutter and lifted it slightly. Just enough space to squeeze through. I turned my body sideways and slipped inside. The smell inside was burnt plastic and dust. I lightly kicked at one of the fallen speakers to check it. Part of the casing had melted. Not from external heat, but from the internal circuit board rapidly overheating. It looked different from mechanical failure. Next to it was a terminal. A data logger. A device that records equipment status in real time. The screen was still on. The battery still had charge. Ren picked it up. I opened the diagnostic log. Back in my original world, I'd spent dozens of hours reading audio management textbooks. The screen layout was familiar. Waveform data, voltage logs, input/output records. At first, I thought, "Ah, the equipment was just old." But it wasn't. The waveform data had a strange pattern. When equipment naturally degrades, the waveform gradually becomes distorted. But this log was different. Only a specific frequency band was abnormal, periodically, in a regular pattern. As if someone had deliberately chosen to target just that part. And there were encrypted markers embedded in the data. Like a program signature. Evidence that something had been sent into the equipment from outside. (…This was hacked.) Ren froze, still holding the terminal. It wasn't simple failure. Someone had deliberately killed this equipment from the outside. And they had technical skill. Pinpointing a specific frequency band to destroy the machinery. That wasn't something just anyone could do. Ren committed that pattern to memory. (I'll call it the Void Sign.) I gave that trace—like a cipher, yet undeniably real—my own name. My own way of calling it. Either way, I needed to remember this pattern. I looked across the ruined stage. Someone had performed here. A stage made for someone, by someone. Now it was just wreckage. (Something is being systematically destroyed in this city.) There was evidence. This wasn't a single mistake. There was no reason to launch such a precise cyberattack randomly. There was a target. A deliberate one. Ren carefully placed the data logger back where it was. It was evidence. I shouldn't take it. --- When I stepped outside, night had fallen. The sky had darkened without me noticing. Even in darkness, Lumière City was bright. Neon lights shone everywhere, and the LED screens on buildings continued streaming live footage. The distinction between day and night seemed thin in this city. Ren leaned against a wall and sat down. In the shadow of scrap metal. A place where no one could see me. For a while, I just stared blankly at the stage wreckage. (…This is the worst.) To be honest, that's what I thought. I didn't know how to get home. I didn't understand this city's rules. No money, no phone. A drone had chased me earlier. The more I tried to organize the situation, the clearer it became how trapped I was. I remembered winter of my second year in middle school. The year my parents divorced. Life just continued after that, though. I was left at my father's house, and my mother called me to hers on weekends. Both had proper meals, proper rooms. But neither felt like "home." That winter, the sense of having a place to belong faded from inside me. That's why I started studying music production. The reason was simple. If I could create someone else's stage, I could find meaning even without a place of my own. Not sitting in the audience, not standing on stage, but creating the stage itself. And now that same person was alone in a city no one knew. Ren hugged their knees and rested their head against the wall. Night wind passed through the narrow alley. Music from somewhere drifted from far away. An idol song. It seemed to play even at night in this city. (The Void Sign.) That came back to my mind. That pattern was real. Somewhere in this city, someone was still moving. Destroying equipment, crushing stages, breaking something. Ren had no way home. No money. No one I could trust yet. But that cipher pattern alone—I'd seen it with my own eyes. My knowledge of music production had finally, truly functioned here. It might be useful. Too small to call hope. But better than nothing. Something that barely kept Ren standing in this night. Ren slowly got to their feet. I checked the ID card in my pocket one more time. 765 PRODUCTION / PRODUCER ID. I didn't know what this card meant. But someone in this city had issued it. (Let's go.) Ren started walking toward the alley's exit. The night sky of Lumière City was stained with neon light. Idol live footage was still streaming somewhere on a building. Something was happening in this city. That was the only thing certain to Ren right now.