The semiosphere is a kind field that covers earth. It is create and actually made up of information, and as such, it only really exists ever since humans have developed conscious minds that can comprehend thinks like memory, ideas, concepts and abstraction.

It actually exists in a kind of different plane of existance, but in certain circumstances, a process called Thickening can occur.

This is when suddenly, there is a major paradigm shift within human society and the way they process information, for example, the first time they invented writing, or, as is the most recent case, the extreme steps communication technology has taken.

These cases can be thought of as if the semiosphere is a container, that can only grow with a certain speed, and if it's filled with more information and ideas than it can take, the pressure rises. If it rises too much, the ideas and informations and believes it's made up of start to influence reality, and if the Thickening really goes out of hand, what is known as reality will pretty much disappear and become something else altogether, as every thought and word has as much effect as physical actions.

To prevent this, the Semiosphere has natural defenses: Instead of altogether overflowing, certain phenomena appear as sort of valves: The information energy stored can evaporate into the real world in a controlled fashion. The most important of these is Possession , but there others as well.

The stored informational or ideal energy transforms to Semioplasm when it enters the real world, usually. (Or perhaps it's already called Semioplasm all the time, not decided yet.)

With a combination of famousness,willpower and ego, the consciousness of humans (which is also a kind of Information), the very concept of a singular human can manage to imprint himself into the Semiosphere, achieving a kind of semi-immortality. But only if the Ego, that is, the sense of self of that person, is very very strong can he retain a conscious, sentient existance. Otherwise, he or she will simply disperse and become a tiny speck of information in the gigantic flow.

There are various factors that influence the power of a single idea or information in the Semiosphere:

1. How many humans use this concept/ have thought of this idea / know this information (this is what makes famousness and popularity of something a power in the world of Hissatsu)

2. How much / how many other informations, concepts (also works of fiction like books, movies, comics etc.) it has influenced and inspired.

3. How strongly humans believe in this concept / idea

As you believe very much that you exist, Ego, that is, sense of self, has a high chance of existing REALLY powerfully in the Semiosphere. Which is the major reason for the existance of Ghosts/Imprinted Personalities.