The moment his eyes opened, he remembered there was no electricity. Early summer sunlight streamed through a gap in the curtains. It was blinding. But even when he pressed the switch, the lights wouldn't come on. It had been like this for seven days straight. Kaito slowly sat up. A 35-year-old apartment building, Corpo Himawari, second floor. His white shirt was wrinkled, and dust clung to his black slacks. His face reflected in the window glass instead of a mirror—his short black hair was disheveled, and dark circles hung beneath his deep brown eyes. A small scar on his right cheek glinted faintly. His slender 170-centimeter frame felt like it had gotten thinner over these seven days. (This is seriously bad.) That was his honest assessment. A single plastic bottle sat by his pillow. It was about half full. Kaito slowly unscrewed the cap and took just one sip. The cold spread through his throat. The refrigerator had been off for seven days, so the water was room temperature. But he wasn't in a position to complain. He screwed the cap back on and set it on the floor. This was his last bottle. --- Seven days had passed since Zero Day—the day the city's people started calling it that. At first, he'd thought it was just a blackout. That happened sometimes. But it wasn't. It wasn't just electricity. Water stopped flowing. Gas stopped. His smartphone couldn't connect even with battery remaining. The TV and radio showed nothing. The next morning, nothing had changed. The morning after that, nothing either. On the third morning, when he went to the nearby convenience store, the shelves were completely empty. Snack bags and cardboard boxes were scattered across the floor, and the cash register drawer hung open. He tried calling the police, but his phone wouldn't connect. When he went to the police station, no one was there. In the first two days, Kaito had pried open several vending machines in the neighborhood and collected plastic bottles. He knew it wasn't right. But he had no other choice. From the third day onward, he systematically made rounds of convenience stores and drugstores, searching for food. But other people had the same idea, and the shelves were nearly empty. The Self-Defense Forces never came. The government made no announcements. No one came to help. That was the reality of this city—Minatohara City. A regional city with a population of about 320,000. About 180 kilometers southwest of Tokyo. An ordinary city that had electricity and running water. It was supposed to be an ordinary city. Not anymore. Kaito looked out the window. The morning Shiomi Ward—the densely residential area where he lived—was quiet. Before the collapse, nearly 30,000 people had lived here, but almost no one walked the streets. Occasionally, he could see eyes peeking through gaps in curtains. Everyone was holed up inside. (It's only a matter of time before food runs out.) Kaito stood up and shouldered his backpack. He had to go searching again today. --- The morning air in Shiomi Ward wasn't bad. An early summer breeze passed through the alleyways, and it felt somewhat pleasant. On a normal day, he would have thought, "Nice weather." But now, he didn't have the leisure to gaze up at the sky peacefully. Kaito avoided the main street and walked through narrow alleys. A discarded food wrapper lay in the corner of the road. Someone had eaten it in a hurry; the inside was empty. He stepped over it and continued. First convenience store. He pried open the sliding door and stepped inside. It was dark. Only the morning sunlight streaming through the window provided light. He checked the shelves thoroughly, but they were all empty. Only crushed bags lay on the floor. The refrigerated section had its door wide open, and of course, the power was off. Nothing. Second convenience store. Same story. Empty shelves. He even checked under the register counter, and found a single box of cigarettes. He didn't smoke, so it was useless, but he kept it anyway. It might be useful for bartering. Third drugstore. Empty here too. Only the medicine shelves had a few items left, but most were empty boxes. He found a bottle of insect repellent spray on the floor and picked it up. As he walked, Kaito unconsciously touched the scar on his right cheek. Zero Day, the first day. At an intersection where all the traffic lights had gone out, a runaway car had plowed into the sidewalk. Kaito had instinctively jumped into the shadow of a nearby building. The car crashed into the wall and stopped. He survived, but in the momentum of jumping, he'd struck his right cheek against the corner of the wall. The scar had closed, but touching it still felt slightly odd. For seven days since then, he'd managed without relying on anyone. His mother had died of illness three years ago. His father had left in a truck on the morning of Zero Day, saying he'd "be right back," and hadn't returned. Seven days. No word. (It's always been like this.) He thought that to himself, then immediately pushed the thought away. There was no point thinking about it now. When he turned the corner of an alley, he found a broken vending machine. The glass was already shattered, and the contents had been taken. Kaito stopped. He'd checked three places and found nothing. Would today be another blank? (Is it hopeless...?) He didn't say it aloud. But the thought was forming in his head when he spotted something glinting in the coin return slot of the vending machine. He crouched down to look. It was stuck. A 500ml plastic bottle. Someone must have forgotten it, or it had gotten caught and wouldn't come out. He inserted his fingers and pulled it free. The bottle was cool to the touch. It was still sealed. (Found it.) It was such a small thing, yet Kaito stared at the bottle for a while. He'd completely given up hope, so this tiny discovery felt disproportionately large. As he was about to put the bottle in his backpack— Something appeared in the upper right of his vision. --- At first, he thought it was eye strain. But it didn't disappear. A semi-transparent hologram-like screen floated vaguely in the upper right of his vision. It glowed white, with text written on it. 'Survival System Activated' 'Current Score: 12' 'Action Log: Water Secured' 'Score +3 → 15' Kaito immediately looked around. No one was there. He rubbed his eyes. It didn't disappear. He blinked several times, but it remained. (What... what is this?) He cautiously reached toward the screen. His fingertip moved to touch the hologram—and passed through empty air. "...Huh?" He spoke aloud. He tried again, this time at a slightly different angle. Another miss. Higher? Lower? When he flicked his finger, suddenly he felt a sensation like his fingertip was touching light. A thin, soft sensation, like pressing against a membrane. A menu expanded. 'Body Enhancement (Locked)' 'Surrounding Map (Unlocked at Score 50)' 'Danger Sense (Locked)' "...For real?" The words escaped him. He nervously tapped on the map preview. A rough district map of Minatohara City appeared. His current location in the southeast was displayed in yellow. 'Shiomi Ward - Somewhat Dangerous'. The northwest area was orange. 'Tsukishima Ward - Dangerous'. And the northeast commercial district was bright red. 'Kaminari Ward - Extreme' Kaito stared blankly at it. Kaminari Ward—the entertainment district of Minatohara City. The commercial area centered around JR Minatohara Station, which had been the most lively place before the collapse. Now it was dyed red. Why? The next moment, a voice called from behind him. "[surprised] Hey buddy, you okay?" Kaito nearly jumped out of his skin. He turned around. An old man with graying hair stood in the doorway of what looked like an abandoned house. A large-framed man in his sixties, looking concerned. "[serious] I'm fine. Just talking to myself." "Talking to yourself? I've been watching you wave your hand around at the same spot for a while now." The system screen continued to float in his vision the whole time, the map spinning and displaying. The hologram spread across Kaito's upper right, but the old man clearly couldn't see it at all. "[sarcastic] ...Stretching." "Stretching?" "[serious] Yes, my shoulders are stiff." The old man stared at Kaito suspiciously for a while. Kaito maintained as natural an expression as he could manage, though his heart was racing. The number 'Score: 15' continued to glow in the upper right of his vision. "...Be careful out there. Things have been dangerous lately." "Yes, thank you." The old man withdrew back into his house. Kaito let out a relieved breath. (What the hell is this thing, anyway?) --- On the way back to Corpo Himawari, Kaito experimented with the system's controls. As he figured out the direction and angle of his finger movements, he found it surprisingly easy to operate. It was like a game UI. But this wasn't a game. This was floating in his actual vision. Why he had this system was completely unclear. There was no explanation of who created it or what its purpose was. Why it activated was a mystery. But— (If I earn score, I get more information.) That much was clear. The map unlocks at score 50. He currently had 15. He needed 35 more. If he could fully unlock the map, maybe he could find safe routes, places with food, things like that. Once he thought about it that way, something shifted in his mindset. For seven days since the collapse, he'd only thought about "getting through today." The next water, the next food. That was all. But now it was different. He had a goal. It felt like he had a purpose. As he climbed the apartment stairs, Kaito tapped on the red Kaminari Ward display on the map again. It was blinking. Text expanded. 'Armed Group: Volg Gang' 'Members: Approximately 80' 'Base: Mall Nagare (Central Kaminari Ward)' 'Threat Level: Extreme' 'Special Notes: Forced tribute collection from surrounding residents. Public executions of those who resist have been confirmed.' Midway through reading, he heard a sound. A low, dull sound. An explosion. Distant. From the north—the direction of Kaminari Ward. Followed by multiple screams. Kaito's feet stopped on the stairs. (80 armed members...) He'd vaguely known something was happening in Kaminari Ward from around day five of the collapse. He'd been avoiding it. But seeing the numbers spelled out made it feel different. 80 people. The Volg Gang—he'd never heard the name before, but if the system rated them as "Extreme," they were a force controlling the city center. Forced tribute. Public executions. (This is the worst.) "The worst" was the only phrase that came to mind. His brain couldn't process more complex words like "scary" or "dangerous." Just a vague sense of "this is bad" remained. The screams stopped quickly. Wind swept through the apartment hallway. Kaito stared north for a while. Kaminari Ward was about 3 kilometers from here. Close. Too close. He returned to his room and locked the door. --- Kaito's room had few possessions. He'd never had much to begin with, but over seven days, he had even less. The pile of plastic bags that had held food was now down to two bags. Water bottles—three now, including the one he'd found today. He had one camping stove with gas cartridges, but only two cartridges left. Kaito spread out his backpack's contents on the floor to check. Three plastic bottles. Two packets of instant noodles (he hesitated to eat them because water was precious). One can. A lighter. A flashlight. A smartphone with dead battery. An empty cigarette box (the one he'd found earlier). Insect repellent spray. And a first aid kit that had been in the apartment originally. (This is pretty bleak.) His honest assessment. But he didn't say it aloud. He looked out the window. Evening was approaching. The sky was turning slightly orange. Before the collapse, this time of da