No light. No names. Only numbers. In the lowest city of the deep, a boy raises forbidden jellyfish to buy his friend's dream — and every choice can end the story.
No light reaches the bottom.

Claris,the nation of water. Its twenty-third city, Abyssaria,
is the poorest and darkest place in the country.
The people here have no names. Only Management Numbers.
Those who were never made into fishfolk — who remain trapped in human bodies — carry air tanks on their backs, take on the labor no one else will, and buy each day's breath with ration coins.
Every night, in a city like that, Shion closes the door to his basement.
He is raising jellyfish, a creature the state has outlawed.

Discovery means prison. He does it for one reason only.
To buy his friend Calen her chance to become one of the fishfolk.
-A salvation called the Aquatic Serum-
At the age of three, children shed their numbers and receive the Aquatic Serum.
They are given a body optimized for the water, a new name, and a life lived as fishfolk.
That turn never comes for a child born in Abyssaria.
The raw material is running dry. The price climbs by the day.
Two paths remain: spend a lifetime waiting to be scouted,
or post overwhelming results at the National Academy and graduate into a career.
Calen drives her pen toward the second one with the only arm she has.
Shion knows that future does not add up — not on paper, not with the numbers she'll be paid.
So he chose another way. Smuggling.
Features
Live2D character interaction
Click the characters on screen and watch them react.
In some scenes, where you touched becomes part of the story itself.
A meticulously built deep-sea world
The Aquatic Serum and Kairos cells. Management Numbers and ration coins. The fishfolk caste and its jellyfish aristocracy. The Death Zone that forms the ceiling of the world.
Every piece of this setting closes in on the choices its characters make.
Characters
Calen, who wields cheerfulness like a weapon. Shion, who cannot say what he feels. Dalia, the school nurse with no sense of personal space. Formo, the student council president counting down what's left of her life. And classmates who never quite back off.
Note on localization:
The English localization was AI-assisted and human-reviewed. Some phrasing may be imperfect.
※ This game is a text-based visual novel.