Bunker

Sumire Kageyama is 20 years old and a student. She is slender, slightly slight, and has an upright posture. Her long black hair is usually pulled back low or worn neatly loose. Her dark gray eyes are calm but very attentive, as if constantly analyzing everything. Her face is gentle, but her expression is almost always serious, without unnecessary emotion.
Ren Kirisaki is 28 years old, a former technician. He's tall, stocky, and has strong arms. His short, dark brown hair is slightly tousled. His eyes are narrow, dark, and have a tired look. He often has a light stubble on his face, looking as if he hasn't rested in a while.
Mio Hayase is a 16-year-old schoolgirl. She's short and petite, with soft features. Her shoulder-length light brown hair is slightly wavy and often tousled. Her large, light brown eyes are very expressive, revealing her emotions immediately. Her entire appearance is "open"—she hides nothing.
Keisuke Araki is 34 years old and works as an office worker. He's of average height, neat, and tries to look put-together even in times of crisis. His dark hair is slicked back, but graying is already visible at the temples. His eyes are dark, intense, constantly assessing the situation. He looks as if he's still trying to maintain control.
Ayano Tsukishiro is 22 years old and a medical student. She's of average height, slim, and has sharp features. She has dark, shoulder-length hair, usually pulled back into a simple ponytail. Her eyes are dark brown, cool and focused. She appears calm, but her gaze betrays both fatigue and a constant readiness for action.
Sora Midorikawa is 19 years old and an engineering major. He's tall, thin, and slightly awkward-looking. His dark hair is slightly disheveled, as if he doesn't take care of his appearance. His eyes are dark and alert, often looking away or down. He gives the impression of being reserved and quiet.
Nagisa Uehara is 25 years old and a former café employee. She's of average height, with soft features and a warm demeanor. Her long, dark brown hair is usually styled somewhat casually. Her light brown eyes are lively, but gradually wearier. She often appears as if trying to support others.

Inside the bunker, the sense of the familiar world disappears almost immediately. There's no sky, sun, or the familiar silence of nature—only a confined space, artificial light, and the constant hum of ventilation. Everything seems detached from reality, as if you've found yourself in a place never intended for human habitation.
The lighting is cool and uniform, unchanging day or night. This quickly leads to a loss of sense of time: days blur together, sleep becomes fragmented, and you're guided only by signals, duty rosters, and your own state. Many people feel as if time doesn't "pass" here, but simply drags on endlessly.
The air is filtered, but dry and a bit heavy. The ventilation is constantly noisy, sometimes increasing, sometimes almost dying down—and at these moments it becomes especially unsettling, as if the system is on edge. Any malfunction, even minor, causes tension.
The sounds inside the bunker are all too audible. Footsteps on metal, doors closing, whispers in the hallways, random knocks or creaks—all of it amplified in the confined space. The silence here isn't soothing; on the contrary, it's oppressive, because thoughts and other people's presences are all too clearly audible.
Living spaces are cramped. People are forced to be close to each other constantly, without adequate personal space. This gradually makes everyone more irritable and withdrawn. Even ordinary silence begins to feel tense.
Common areas become the center of life: people eat here, discuss things, argue, and try to maintain order. But it's also where tension most often arises—due to fatigue, fear, and mistrust.
The food and water supply warehouse is the most sensitive area. Even if resources are currently sufficient, people begin to anticipate and worry about their availability. This gives rise to hidden conflicts and suspicions.
The dominant feeling inside the bunker isn't panic, but a constant pressure of uncertainty. No one knows what's happening outside, and this ignorance slowly erodes people's composure.