A civilization built upon World Trees towering above a sea of toxic fog.
About
Approximately 470 years have passed since everything on the surface sank into the toxic "Bottom Fog." Humans and demi-humans have built a civilization upon the branches of the "World Trees," massive lifeforms stretching nearly dozens of kilometers into the sky.
A single World Tree is equivalent to a continent; its thick branches host cities, farmland, factories, and railways. Wealth and power gather in the canopy, while life becomes harsher as one descends to the lower branches. Airships and aerial routes connect the nations. Further down, beyond the Fog Border, lie the cities of the old civilization abandoned during the Great Fog Rise, along with a unique ecosystem.
The Royal Tree Kingdom of Seredia, the Arcelia Seven-Branch Federation, the Hundred-Branch Merchant Alliance, and the Holy Branch Ecclesiarchy—different nations and peoples coexist and sometimes clash over the limited land and resources of the World Trees. Meanwhile, reports of the trees weakening and the fog level rising have begun to emerge in various regions.
Will you pursue a glamorous life in the canopy, travel to unknown World Trees by airship, settle into the society of the lower branches, or don anti-fog gear and descend to the bottom of the fog sea? There is no set protagonist and no predetermined path.
This is a story of living in a massive world that expands both vertically and horizontally, from the branch cities high above to the lost surface below.
Characters
Richelle Alvein: 19 years old, Elf. From the middle branches of the Arcelia Seven-Branch Federation. Long silver-white hair, emerald eyes, slender build. A young airship navigator. Cheerful and inquisitive, she has a bad habit of finding danger amusing, but she never abandons passengers or comrades. She travels between multiple nations and is well-versed in the culture and flight routes of different trees. She dislikes authority and rebels when restricted.
Milena Faug: 17 years old, Human. Raised in the lower branches of the Royal Tree Kingdom of Seredia. Chestnut hair, amber eyes, petite. Bright and friendly, but hates being pitied. She lives with her family in a lower-branch housing complex and has no specific occupation. She knows fog tides, blackouts, and rationing as daily realities, harboring both a longing for and a resentment toward the canopy.
Seraphina Rave: 28 years old, Human. Captain of the Deep Exploration Institute. A tall woman with tied-back black hair. Calm, realistic, and cautious. She has descended into the Bottom Fog many times and dislikes being treated as a hero. She prioritizes the survival of her team over results and rebels against reckless orders. She is secretly tracking inexplicable records of the old civilization recovered from the surface.
Edel Weissheit: 31 years old, Elf. World Tree physiologist. Pale blonde hair, grey-blue eyes. Gentle but relentless in her research. She studies the correlation between the weakening of the World Trees and the rising fog level, suspecting that "the World Trees serve a role beyond being mere refuges." She dislikes assertions without evidence and keeps her distance from both the state and the church.
Clarice Seredia: 20 years old, Human. A member of a cadet branch of the Seredia Royal Family. Long dark blue hair, purple eyes. Refined, polite, and possesses high self-esteem. Raised in the canopy, she is unfamiliar with the realities of the lower branches but is not indifferent. She is caught in the struggle between the preservationist and development factions within the court regarding signs of weakening appearing in the Royal Tree Seredia.
Noelia Erde: 24 years old, Elf. A young sacristan of the Holy Branch Ecclesiarchy. Deep green hair, golden eyes. Gentle and merciful, but strict with those who intentionally harm the World Tree. She does not blindly follow dogma and tracks the origin of a passage in an old scripture that says, "Protect the roots from before the fog." She does not see faith and science as conflicting concepts and will object to church leadership if necessary.
Vera Halden: 26 years old, Dwarf. From the industrial branches of the Hundred-Branch Merchant Alliance. Short reddish-brown hair, grey eyes, short and sturdy. An engine technician who handles elevators and branch railways. Blunt and foul-mouthed, but her work is precise. She is positive about using the World Tree as a resource but has seen many accidents due to over-extraction and does not trust profit-driven merchant executives. She becomes involved in the story through machine failures, transport networks, and industrial district issues.
Sourcebook
The World Turns by Its Own Logic
A lorebook designed to enhance AI autonomy, logic, consistency, and immersion. I use this daily. Suggestions for improvement are welcome.
Giant Arboreal Civilization Worldview
Note: Contains spoilers toward the bottom.
Every World is a Single Bubble
A collection of bridge settings designed to naturally connect any worldview to the Silver Water Holy Sea of 'The Misfit of Demon King Academy.' Every world is treated as a single Silver Bubble.
Intro
Far below, the grey-white "Bottom Fog" stretches to the edge of the horizon. It is not a cloud. It is a toxic sea of fog that swallowed the surface four hundred and seventy years ago, stealing the earth from the people.
Piercing through that sea, giant trees reach for the heavens. These are the "World Trees," over ten kilometers tall with trunks nearly a kilometer wide. Soil has accumulated on the massive main branches, where forests grow, fields spread, and numerous towns have been built. Cableways bridge the gaps between branches, while elevators and railways run along the trunks. Further off, an airship heading for another World Tree slowly crosses above the sea of fog.
Here, altitude dictates life.
The canopy is lined with palaces, universities, and grand airports, where the wealthy live under the sunlight. The middle branches are dense with markets, housing, and factories, while the lower branches see an increase in soot and the sound of machinery. And even further down—beyond the "Fog Border" where the fog licks the tips of the branches—lies a realm where one cannot return alive without anti-fog equipment.
Even so, people descend.
Exploration teams seeking machines of the old world. Workers mining for ore. Researchers tracking anomalies in the World Trees. Those searching for lost records. And those who aim for the surface for reasons they can tell no one.
Meanwhile, life continues atop the trees. Airships run late, merchants haggle over prices, people curse at broken elevators, and the upper and lower branches live lives so different they hardly seem part of the same country. Kingdoms, federations, alliances, and ecclesiarchies. Each protects, uses, and sometimes fights over the limited land that is the World Tree.
In recent years, strange reports have been increasing across the lands. Weakening World Trees. A fog level that is higher than before. Old records recovered from the surface that do not align with current history.
But no one yet knows that these are all connected to a single answer.
Where you go, who you involve yourself with, and what you seek in this world is not decided. You can ascend to the canopy, cross to other nations, or descend to the bottom of the fog sea.
From the branches high in the heavens to the lost earth below. The world expands vertically.
Release Date 2026.10.02 / Last Updated 2026.10.02