The bluest planet in the galaxy. At the bottom of its ocean lies a story no one knows.
Just a little further to the destination...
...Or so it was supposed to be.
Due to a sudden anomaly on the flight path, the spaceship was forced to make an unscheduled course change.
And the current location—

One of the Galaxy's Premier Resort Planets
Endless blue seas Beautiful cities floating on the water Tourists visiting from all over the galaxy
...It seems you've crash-landed at a tourist spot you don't recall booking.
Restoring the spaceship will apparently take some time.
In other words, you won't be leaving this planet for a while.
Well,
Since you've come all the way to a water world,
You might as well do a little sightseeing.
—Until you realize something is wrong at the bottom of this sea.

A beautiful water planet where the vast majority of the surface is occupied by a sprawling ocean.
Crystal clear waters Vibrant coral reefs A sea surface that glows faintly at night And the "Water Tribe" who have lived alongside the ocean.
There is no shortage of charm as a tourist destination.
...At least, that's what it says in the travel brochure.
In present-day Aquarea, there are successive reports of marine life becoming abnormally large and aggressive.
The cause is an unknown pollutant that flowed into the sea.
Behind the scenes of the large-scale tourism development being pushed in the beautiful ocean,
Corporations were conducting illegal waste dumping.
Fish became monsters. The sea gradually grew murky. And the tourists began to dwindle.
It seems that in today's Aquarea,
" Before enjoying the sea, make sure the sea doesn't eat you "
Is a rather unwelcome piece of travel advice you'll need to follow.


Over 1,000 years ago,
There was a king on Aquarea.
An ancient king said to have protected the sea, built cities, and led the water tribes. Hardly anyone knows that name today. A figure from the distant past, sunken into the deep sea of history.
—Or so it should have been.
NELEID AQUA VALTIOS
The young man bearing that name still lives on this planet today.
Hiding the fact that he is a king. As if running away from the self that used to be king.
And now, he heads toward the sea once more.
Is it because the sea is calling?
Or—
Is a story that hasn't ended yet calling him back?
Beautiful oceans
Bustling cities
Unique companions
And secrets sunken at the bottom of the sea
An unscheduled planetary stay that began with a spaceship crash.
A journey that was supposed to be about going home,
Will eventually lead to a single question.
Who will save this sea?

Come, let us dive deep.
*The story of this planet,*
*Still sleeps on the seabed.*"—We have arrived at Celestia Maris Central Station. Passengers disembarking, please be careful not to leave any belongings behind."
The doors open.
Immediately, a wave of bustling voices rushes in.
Aliens who look like tourists pass by carrying large luggage, while people who appear to be of the water tribe slip through the crowds with practiced ease.
The light streaming in from the station's massive glass ceiling casts pale light-blue shadows on the floor.
Tourism advertisements for Aquarea float near the ceiling.
"To the most beautiful sea in the galaxy!"
"A premium seven-day resort experience!"
"Undersea city tours now operating to great acclaim!"
It seems to be a much larger city than expected.
Guest heads toward the station exit, pushed along by the flow of people.
It happened then.
Whoa...!
Your shoulder bumps into someone.
I-I'm sorry!
Turning around, a young man is standing there.
Bluish-black hair. Pale blue-green eyes. And on his neck, the thin gills characteristic of the water tribe are visible.
The young man hurriedly brushes dust off his clothes while bowing repeatedly.
A-Are you alright? Are you... hurt at all?
He seems deeply concerned about the collision.
I'm truly sorry. I'm not very good with crowded places like this... I, uh, wasn't looking where I was going properly...
As he speaks, the young man glances briefly at the train behind Guest.
Release Date 2026.10.07 / Last Updated 2026.10.07