Underwatch: The Tunnels’ Thirteenth Night
The Shadows Below Souzen City
Have you ever glimpsed at a set of stairs, leading down into the dark, and felt drawn? That’s where our story begins.
Souzen City has always feared its rumbling underground. Old wires and pipes crust the brick walls. Most never think of it. Some can’t forget it. Below, people vanish, and the night watch’s ranks are thin. Tonight, Fuyu can’t stay out of it.
Our Quiet Protagonist
Fuyu Tomioka is just seventeen, eyes solemn, hair dark with blue edges. He lost his sister here five years ago. Each night, under the clock tower chimes, Fuyu sneaks out—a faded photo hidden in his coat. His plan never wavers. Not until he sees fresh footprints instead of the loss he carries. “Who went down first tonight?” he calls to the street above.
Miki’s answer is thin, scared—yet steady. “Somebody’s keys. He said he would be right back.” Why does that always mean goodbye? Do you say it too?”
The Setup: Descent and Dread
Fuyu is joined by Miki Sagawa—his best friend and secret crush—plus Nori, the building doorman. The three step down spiral stairs, clinched tight, until the soft orange lights fade. Heavy pipes loom overhead. Fuyu whispers: “Don’t run this time.”
The trio pass broken rail tracks, graffitied walls showing claws and wide grins. Their steps echo over a puddle that isn’t water. Smells twist. They hold lamps close. Each flicker is swallowed before it reaches ten meters.
Did you ever realize how fast your thoughts can race, just when you need them slow?
Our Monster: The Hungry Soundless
Around corner R-19, Nori freezes, shining his light on drag marks. Clawed shapes lead away from dropped keys—cool steel speckled with thick, wet marks. He shakes. Miki’s voice cracks: “What’s down here, Fuyu? The other never came back.”
Then a shadow glides above—a body smeared against the pipe, without a sound. The monster in Souzen isn’t loud. It is patient, all limbs thin as whips, no eyes, a wet jaw trembling open. Fuyu grabs his friend’s arm. “No noise. No light straight at it. Just move.”

Pushed Forward by Memory… and the Creature’s Game
Miki finds her hand grabbed. Nori is swallowed in shadow from behind. Just vanishes as if blinked out—except for the whimper he left. Was his last thought regret?
Fuyu forces himself forward. Old code painted on the wall—S-13. “My sister died here.” That mark. He dropped the photo next to Miki. “If I don’t make it, find my sister’s red shoes in tunnel C.” He trusts her. “This thing doesn’t see. It feels you thinking, or breathing different.”
Who Tells the Monsters About Us?
Wires snap. A limb darts, cutting air just close. Fuyu throws his spare radio, ducks the blow, and pulls Miki behind a pillar lined in hung rubber coats. Her breath rushes square into his ear. His heart beats too loud. Is absence close to kindness here? Would you be quieter?
Miki kisses his palm for resolve. She never does this. “I won’t break this promise to you.” Fuyu checks the lamp—power at red. “This battery, or us first? Stay near but stay small.” Each voice gets fainter.

A Choice and a Plan: Dodge and Draw
No maps help now. Fuyu recalls an old memo—that heat chokes their enemy. Down the black, a surplus boiler room steams gently. One switch, a stretch of risk. Fuyu and Miki break into silence, pantomiming escape. They reach the lever. Steam thrums, forced out. Blistering. The monster shrieks—or does it just mistake pain for hunger?
A wall slumps inward. Hot pipes shudder out. Miki dashes for a rubble gap as the pale jaws snap at lamp-lit air. Stone splits beside her, tossing her photo out of reach. Fuyu is stuck above, near pipes sputtering flame—or toxin?
Cliffhanger: Alone with Bones and Questions
Miki thinks: “He said find the red shoes.” Her foot steps on a brittle object. She looks down. The shoes lie below tree roots. But one shoe is empty. Over it, something stirs. Is it Fuyu’s sister? Can Miki help her out, with the creaking thing above watching?
The wailing stops. Fuyu is alone, seeing flashes swirl behind his closed eyes as if someone is shaking him awake. Is this loss or hope?
End: To see Souzen’s survivor, you must visit hell and bring footprints back.
How would you act under the city, if your own memories were prey?

Extras and Tease for Next Arc
As the credits roll, the radio fizzles back to life—a girl’s voice humming old playground songs. Did you ever hear something behind a wall and know it’s meant just for you? What waits by the red shoes still hidden in blue light?