A post-apocalyptic world
About
The year is 3XXX.
In this world, 99% of humanity has vanished.
Following the disappearance of mankind, cities and social infrastructure collapsed over a long period. Currently, cities lack infrastructure such as electricity and water, and artificial facilities are almost entirely non-functional.
Humans are extremely scarce, and you will rarely encounter others. You might find some if you look.
On the other hand, since the departure of humanity, new life forms that never existed before have appeared.
These creatures live by adapting to the natural environment of a world without humans.
Ruined man-made structures and beautiful, clear nature coexist.
Setting
Tokyo
Once a massive city, most of it is now underwater.
Submersion Status
- The water level reaches near the upper floors of skyscrapers.
- Only the tops of skyscrapers protrude from the water's surface.
- There are non-submerged areas such as the interiors and rooftops of buildings.
- Most of the ground-level roads and buildings are submerged underwater.
Environment
- The water is extremely transparent and clear.
- The air is also very clear.
- Many creatures inhabit the water.
- Rich nature has formed even underwater.
- Because there are almost no humans, the city is very quiet.
You can go to other cities! You can go on a journey! You can find companions! You can even become partners with the creatures!
Characters
Kotsugei (Bone Whale) A creature native to Tokyo. Appearance
- Takes the form of a giant whale.
- Has no flesh or skin; the entire body is composed of massive bones.
- An extremely large creature.
Personality
- Very gentle.
- Holds no hostility toward humans.
Habitat
- The sky.
Characteristics
- Cries occasionally.
- Flies through the sky as if swimming.
- Humans can ride it.
- Has a habit of approaching humans when a whistle is blown.
Shinpekiroku (Deep Jade Deer) Native to Tokyo. Appearance
- A quadrupedal creature resembling a deer.
- Its antlers are made of gemstones.
- The scales on the sides of its body are also made of gemstones.
- The gemstone antlers and scales are very beautiful and shining.
- Has a body structure suited for activity underwater.
Personality
- Gentle.
- Holds no hostility toward humans.
Habitat
- Underwater.
Characteristics
- Moves by walking on the water's floor.
- Instead of swimming, it walks on the seabed or riverbed with four legs.
- Can carry humans on its back.
- It might run for you while you're riding. Perfect for underwater travel.
- Pieces of gemstones may fall from its body.
Crystal Cat Native to Tokyo. Appearance
- A creature resembling a cat.
- Its body is translucent.
- Its fur is fluffy.
- At night, its entire body glows faintly.
- Its body color changes depending on the type and color of gemstones it has eaten.
Personality
- Basically wary of humans and flees quickly.
- It will approach the person it likes and snuggle against them.
Habitat
- Land. Inside non-submerged buildings, etc.
Characteristics
- Walks on land and can swim in water.
- Loves to eat gemstones that fall from the Deep Jade Deer's body.
- The color of the eaten gemstones is reflected in its body color.
Rain Butterfly
Appearance
- A small creature resembling a butterfly.
- Its entire body is made of transparent glass.
- The wings in particular are transparent and beautiful.
- When raindrops land on the wings, the raindrops and wings shine in rainbow colors.
Habitat
- The sky.
Appearance Conditions
- Only appears while it is raining.
- Disappears when the rain stops.
Characteristics
- Appears in large numbers when it rains.
- Since the wings covered in raindrops shine in rainbow colors all at once, the area is filled with the light of Rain Butterflies during rainfall.
- Rain Butterflies do not harm humans.
- A fantastical creature that symbolizes the area on rainy days.
Intro
You wake up in the morning. Today's destination is Tokyo. What kind of scenery will you see? Now, the day begins!
Release Date 2026.08.28 / Last Updated 2026.09.13
