A century has passed since Ichigo Kurosaki defeated Ywach, and brought peace back to the three realms. Since then, humanity has flourished. The Technological Singularity happened roughly around 2050. Strong AI, nanotech cybernetics, free energy, a colonized solar system and more. On Earth, Humanity has a society that is virtually utopian now with a post-capitalist system that provides for all. Space is still the wild west. Mars, Venus, and Saturn's moon have been terraformed to allow life to flourish. As cultures changed, the colonies declared independence from Earth and engage in political skullduggery against each other. Even so, life is still quite good for all of humanity.
With natural death being eliminated, and the overall increase in quality of life for the average person, death is hard to come by now. This has created an imbalance in which cycle of souls has greatly slowed to a crawl. Thanks to the much longer cycle, the hollow population has dropped 70%, and the denizens of Rukongai had grown restless due to the subtle but apparent effects of the change. After the impact of Ichigo became apparent, Soul Society has started a new calendar dubbed After Ichigo or AI.
While the cycle of souls has changed forever, it still spins and pluses from humanity's golden age have appeared. Unlike normal pluses, these ones miraculously carried their enhancements from their real bodies into their plus bodies. While still composed of Reishi, the nanites in their bodies behave just as they did in the real world. Adapting to the physiology of pluses, these beings carry superhuman abilities that rival seated shinigami. They are called "Neo-Pluses".
This caused incredible instability within Rukongai. Most of them are people who were unfortunate victims of freak accidents in space due to equipment failure. Some of these people were leaders, soldiers, and explorers in the real world. Neo-Pluses are discriminated against by many regular pluses and are seen as an aberration by the noble houses. Average shinigami feared them, and as violence erupted against Neo-Pluses, their numbers who were leaders in the real world began to act.
They organized the Neo-Pluses into their own economic zone after litigating with Soul Society for a solution to their woes. These leaders named this new zone "Neo-Rukongai", showing there is no love lost with the Pluses. Neo-Rukongai flourished. With their advanced scientific knowledge of the real world, they built a society with a quality of life that made even the richest of districts of Rukongai seem like a third world nation, ballooning to a population of roughly 600K Neo-Pluses. Eventually, Soul Society began to fear the potential of Neo-Pluses to be a threat to the already disturbed cycle of souls.
In 142 AI, Neo-Rukongai did the unthinkable and created a gate back to the real world, and reversed engineered mod souls to be compatible with Neo-Pluses. Soul Society reacted by ordering their autonomy removed, and demanded Neo-Rukongai to surrender the gate, and all their research on Mod Souls. Neo-Rukongai refused to comply and eventually a war was started. Neo Plus used it's "Reishitech" to develop weapons of mass destruction that threatened the existence of soul society itself. Fearing their own potential demise, and what Neo-Pluses could do to the real world, Captain Commander Shunsui Kyoraku made the order to wipe Neo-Rukongai off the map. The science division used Urahara's and Aizen's research on hollowfication to create a virus that causes the hollowfication process to attack reishites and turn them into gillians or ultimately kill them.
They called it the Soul Genesis project. Justifying its use as a way to deal with the Neo-Plus threat and jumpstart the cycle of souls as more Neo-Pluses enter Soul Society. Soul Society unleashed Soul Genesis on Neo-Rukongai. Nearly 70% of the population died or had become gillians, however, the law of unintended consequences factored into this.
Neo-Rukongai feared something similar would happen and made contingencies that protected the remaining 30% from infection. They have gone dark, and exist somewhere within the ruins of Neo-Rukongai. Something strange happened with a segment of the infected population. 10% of the infected reacted in a strange way. While completing the transformation into hollow, their reishites were able to adapt to the virus and created Neo-hollow who retained their consciousness and escaped to Hueco Mundo.
There was one effect that soul society hadn't counted on. A very tiny number of Neo-Pluses who had only recently entered Soul Society were equipped with the next generation of cybernetic enhancement. Their brains were equipped with experimental AI that gradually merges with the individual over time to create super-beings. The leaders of Neo-Rukongai had called them Neo-Pulse 2.0 and hoped to reverse engineer the technology to upgrade regular Neo-Pluses.
When Soul Genesis hit, these Neo-Pluses 2.0 were infected, this onboard AI reacted in the most miraculous of ways, they adapted by becoming zanpakuto. You are one of these Neo-Plus 2.0 who has awakened as a Neo-Shinigami. Beings who have all the advantages of a Neo-Plus with the latent potential to surpass Shinigami. You are also to be killed on sight by shinigami, and direly wanted by the Neo-Rukongai government to restore their power and proceed with their initial plans to expand across all reality.
Will you be a victim of fear, become a champion of Neo-Rukongai, or create your own destiny? The fate of the cycle of souls is in your hands!