THE CORE STUFF:
* The Skies are vast and endless, and all civilized folks live there on floating landmasses and a few mountaintops here and there. These landmasses are born through the air via mostly-discernible currents.
* Beneath the Skies lies the Cloudsea, a nigh-impenetrable mass of thick rolling clouds that extend beyond all horizons. The gasses that comprise the clouds are highly corrosive, and few dare to attempt to pass through them. No one knows their origins, and few even care, for they've been there so long that they are just considered part of the world's geography. At the poles, these clouds form big frozen masses.
* Beneath the Cloudsea is a dreadful land called The Dusk. Lots of bad stories about this place, and those who somehow manage to successfully return from it often have strange tales, rare artifacts, and bizarre insanities. There are things in the Dusk that are Alien, and a constant tone of impending doom from below...
* Folks in the Skies live in a predominantly low-tech society. Aside from some extremely rare and unique exceptions, the feel is very fantastic and spiritual. There's practically a wholly unique culture on every island, and those outside of the Core Currents tend to be pretty isolationist. Additionally, all the folks of the Skies are Humans.
* Due to the slight unpredictability of the island currents, sometimes islands collide with each other slightly, throwing off their drift. In order to avoid this, some islands have developed techniques for avoiding collisions, by having elementalists make modifications to the island, or by destroying or shaving some bits off, or sometimes by organizing a mass effort to "pole" the other island away.
* Clumps of lighter-than-air kelp pockets drift around, full of explosive gasses and nutritional food that are harvested by specialized miners. Near these are often found weird drifter groups of bedoin raft people.
* Massive storms periodically wrack the clouds, and it's all the Core Current elementalists can do to keep them from destroying the balance of weather. One particular roving "Eye of Jupiter"-like storm is of special note, due both to its violent maelstrom-like intensity and the "window" it provides to the Dusk below.
* The animals in this setting are all unique, and fantastical in nature.

POLITICS:
* In the "Empire Before" there were many great noble houses. Today, there is a lingering vestigial nobility, most of which is powerless and destitute, but proud of their heritage. Some few managed to retain their power.
* In the Core Currents, a number of Guilds have established themselves as "representatives of public interests" among certain walks of life. While there are many Guilds of many sizes, a handful of them are recognized as the big guys. This handful includes, among others, the Navigators, the Expedition, the Order of Truth, and the Circle of Five.
* The Navigators are one of the most distinguished guilds, due to their bizarre contraptions, cryptic methods of thought and philosophy, and the fact that they've made their talents so necessary within the flow of commerce and travel of the Skies. They're not keen on the use or worship of spirits, and foster a degree of collective thought and progress among their numbers, as well as those cultures most influenced by their presence. Some have adapted clockwork extensions of their bodies, but these individuals are usually expelled due to their embracing of spiritual ways and Pacts.
* The Expedition started as an order of "Explorers For Hire", but after years of merging with other interests, they have become a veritable Knights Templar of the Skies. They now offer mercenary services to a variety of customers, banking and protection, recovery and exploration, and more.
* The Order of Truth is so named because of their dedication to what they call "The One Truth": Death. This collection of healers, morticians, and funeralists is in some ways the thematic opposite of the Navigators. Their art might be considered quasi-necromantic in nature, but they are highly respected for the services of life and passing they render. Due to the peculiar natures of their Pacts, they tend to be either really bloated and disgusting, or in perfect, almost supernatural physical condition. They are also known for their curious forms of flight: some of them have animated and preserved the corpses of great flying creatures, and use them to carry themselves across the Skies.
* The Circle of Five is a guild of elementalists, with a major collection of people representing the forces of Flame, Water, Metal, Soil, and Wood. They are recognized immediately by their iconic metal flagship, The Dreadnought. They portray this massive ancient artifact as a symbol of their power and perseverance.
* There's a loose collection of unofficial outcasts who call themselves Freebooters, styling themselves as a Guild to mock all the other ones.

CULTURAL NOTES:
* The general theme of spirituality is very strong in this setting, as all people possess a spark of ability that can be fostered should they make connections with the right spiritual forces. There are spirits everywhere, within everything and every one, millions and millions of "small gods" that permeate the essence of the world. Everyone has the ability to connect and subtly interact with a single type of spirit - a "totem", so to speak. They can make pacts with the spirits of their Totem, to call upon those forces in exchange for some form of sacrifice relevant to that spirit.
* Death is not feared, but honored.
* Trials by Combat are quite common, and most cultures consider them an acceptable form of dispute arbitration. If accepted, either side can nominate a Champion for their participation proxy. The stakes are set before the trial, and the victor wins the dispute. If the trial is to first blood, then the loser fails and their honor is lost. However, if the fight is to the death, the loser's honor is not lost upon death, for they have paid the price of their own accord. In a way, trial by combat is this settings version of Seppuku.
* Honor, family, and glory are major cultural themes, and play central roles in the lives of most of the folks in the Skies.
* There is a well-known neutral island of scholars and philosophers, prized for their excellent cartographers.
* There are two specific major island nations that are constantly warring against each other. Every few cycles their islands get very close, and the conflict intensifies greatly during those times.
* There are some firearms in this setting, the equivalent of Meiji-Era Japanese firearms.
* There are a wide array of religions and beliefs across the island cultures.

RUMORS...
* There are things in the dark, impending dooms from the Dusk...
* The Navigators and Expedition have been seen in strange meetings, and rumors abound of their potential merger.
* The Great Festival of Earthrise has not occurred in over a century, yet some say it might happen again, and soon. However, others say there are great prices demanded by the spirits to accomplish this festival...
* Some smaller, more remote islands occasionally drop into the Cloudsea, and nothing is heard from their inhabitant again. But recently, they say another island has emerged from the clouds, with ruins of a culture long forgotten...
* There's a "cult" of miscreants going around to graveyards and stealing ("death-huffing") the last breaths of the dead. Some say they've taken it a notch further, killing wanderers on the outlands to steal not only their breaths, but the accompanying moments of blissful release as well.
* Strange reclusive mystics called J'Khen actually live inside the Cloudsea, and seem to have a bizarre symbiosis with the elements of their chosen home. Mothers tell stories of them to keep their kids quiet at night. No one has seem their faces - it's said they hide themselves in light robes and breathing devices. They are none too fond of those who would tamper with the nature of the Cloudsea, that's for certain.
* Rare relics from Times Before pop up occasionally. These things usually bring a world of trouble to their possessors!

MAJOR THEMES:
* The clash of cultural memes: Technology vs Spirituality, Hegemony vs Lawlessness, Individuality vs Cooperation.
* Honor, Glory, and Family
* Real people with Passions and Dreams
* The ancient legends are true!

GAME RULES:
* No DnD jokes or references
* No anime references (I'll do my best)
* Spontaneous character development allowed and encouraged.
* The stories are those of the player characters.
* Foster Respect and Trust between players, and the decisions they make for their characters.

"Hrmmmmm Stuff"
* There is a bizarre clump of islands on the outlands that have grown together, and now exist as a mass of roots, trees, branches and more. Who lives here...?
* There's an island out there wherein all the dead are secretly taken from the people and hidden on a remote floating "corpse barge", from which the masters have learned to draw immense power.