The Great Seiyuu Age — there was a period in time that earned itself that name. Seiyuu became the stars of the day, the hopes of humanity — all envied their laryngeal sacs. Seiyuu of the day were in demand for far more than just their main job — they were called on for pin-ups, modeling, singing, and streaming video performances.
The history of seiyuu was a long one. One theory placed the origins 500,000 years ago, as early as the birth of homo sapiens. That being said, seiyuu of the past were natural seiyuu, and did not have laryngeal sacs displayed outside the bodies. It was unlikely they could do more than gather a few dozen together to light a bonfire.
The origins of seiyuu evolutionary theory and the biological mechanisms involved were shrouded in mystery, even today. The best guess anyone had been able to make was that the laryngeal sac had been the key to everything. Natural seiyuu could not be identified as such from appearance alone, but they, too, possessed a laryngeal sac the size of a thumb on the interior of their throats. The presence of the laryngeal sac alone granted them control of aether vibrations.
While the principle behind it was unclear, a method was discovered to expand this ability. The Human Genome Project carried out some 270 years ago discovered a gene that could grow the laryngeal sac. In theory, if the sac was enlarged, the seiyuu’s ability would grow by leaps and bounds. It only took twenty years before genetic engineering developed enough to make this theory reality.
Seiyuu genes were exclusive to human beings, and creating enhanced laryngeal sacs involved the birth of designer babies. Some bioethical concerns were raised, but they were defeated by a wave of economic practicality. Effectively, a detailed examination of seiyuu activities revealed that they were able to get around the law of energy conservation. Use of seiyuu made it possible, in principle, to create a perpetual motion machine. Propaganda machines went into overdrive, announcing that the next century would be the age of the seiyuu. The Seiyuu Revolution would be as dramatic as the Industrial one. Seiyuu would lead humanity forward.
Thus, the first generation of artificial seiyuu was born. But their abilities were weaker than anticipated, and their endurance poor. Activating their abilities required lengthy periods of concentration. From the perspective of value and stability, even if they could break the law of energy conservation, they were not worth using for power generation.
The field that did find uses for them was the space industry. Since seiyuu could control aether vibrations, they could manipulate sound, light, and a number of other forces. One of these forces was gravity control — something not possible with any other device. Calculations showed that use of this ability would make escaping the gravitation sphere far more cost-effective. The space industry had always been prohibitively expensive, but the introduction of seiyuu made things considerably cheaper.
Fifty years after the discovery of the seiyuu gene, gravity control spaceships were exploring the solar system, flown by seiyuu pilots — seiyuu were finally stars. In light of which, egged on by designer baby industry advertisements, parents everywhere altered their children’s genes, turning them into seiyuu.
In response to demand, two programs began, both aimed at elevating seiyuu powers. The first was the Legend Class Project, a simplistic approach that attempted to enhance seiyuu abilities by making the laryngeal sac larger. The quality of seiyuu they targeted were referred to as Legend Class, and they insisted these seiyuu would even be able to create antimatter.
The other was the Seiyuu Transistor Program. A seiyuu transistor was a supplementary system designed to work with existing seiyuu abilities. They introduced the seiyuu gene into gorillas, chimpanzees, orangutans, and other anthropoid apes, and when they grew laryngeal sacs, they harvested these, combined them, and created biomachines. They called them seiyuu transistors. The plan was that by merging multiple seiyuu into a single transistor, the power output would be the equivalent of having one giant seiyuu.
Both plans more or less succeeded, and seiyuu opened the doors to travel outside the solar system. This was the dawn of the Great Seiyuu Age. Thanks to seiyuu, mankind began spreading through the galaxy in earnest.
Physics proved no impediment. Physics-based speed limits like the speed of sound or light speed were dependent on the density of aether. In the atmosphere, where aether was thin, 100,000 kph was all they could manage, but in the open stretches of the solar system, where aether was much thicker, they could easily top 1,080,000,000 kph. Once they entered interstellar regions, that jumped to 10,000,000,000,000 kph. Once they made it into space there were no practical impediments to the spread of humanity.
Except for one thing, that is. Mankind made an unexpected and disappointing discovery. There were almost no planets they could safely colonize. To be strictly accurate, planets themselves were far and few between. The law of universal gravitation did not seem to be all that universal. Mankind found very few sectors where gravity worked like our solar system. The aether flow caused any number of places where dust and gas gathered — a.k.a. aether deposits — but it was extremely rare for that matter to mutually attract and form a stable celestial body. There must be more to gravity than previously suspected.
On top of this came more bad news. As the seiyuu investigated the universe outside, they discovered that our solar system lay inside a massive aether deposit. A spiral-shaped deposit a quintillion kilometers in diameter, this was named the Milky Way. The problem was that mankind had no way of leaving the Milky Way. Because the gas and dust in the Milky Way crowded out the aether, the aether density within the Milky Way was lower than it was outside. Much like the difference between the Earth’s atmosphere and the solar system, and the solar system and the interstellar realms. The higher the concentration of aether, the higher the energy of light. Thus far, seiyuu’s control over aether vibration had been able to defend against the powerful light flying around the galaxy. However, light outside the reaches of the Milky Way had energy far beyond their capabilities, and the seiyuu were helpless against it. Ships that ventured beyond the Milky Way were instantly vaporized by the intense light that filled that void.
Because of this, a hundred years after the Great Seiyuu Age began, three quarters of the total human population remained within our original solar system. The age of the frontier spirit was quickly being replaced with claustrophobia.
At this time, the status of seiyuu went into freefall. The major genetic engineering conglomerates used their patents on specific seiyuu genomes to place limitations on certain seiyuu’s reproductive freedom. They established legal precedent in courts to back up these demands.
This led directly to the War of Seiyuu Independence. Seiyuu whose rights had been encroached upon rebelled, with the Legend Class seiyuu in the lead. The overwhelming power of the Legend Class seiyuu allowed the rebels to claim an advantage initially, but lack of resources on the seiyuu side led to the rebellion being squashed inside of a month. Even seiyuu can’t do much without food. The survivors called themselves the Free Seiyuu and set out towards the dangerous heart of the galaxy, where mankind had not yet dared venture. The seiyuu left behind found themselves even more restricted.
The technology to create Legend Class seiyuu was banned, and even the less powerful seiyuu found their rights curtailed. The Seiyuu Surveillance Society, subordinate to the genetic engineering industry and the agency alliance, monitored the seiyuu’s lives so heavily they dictated which shampoo they were allowed to use. As romance with the opposite gender might lead to genetic spreading, it, too, was verboten. Upon reaching a certain age, seiyuu were married to a partner arranged by the Seiyuu Surveillance Society and forced to start rearing the next generation of seiyuu. Any who resisted were severely penalized by the Seiyuu Police. By this point, seiyuu were no longer human — they were merely parts for spaceships, raised like livestock.
Akane was born forty years after the War of Seiyuu Independence, so to her this was all in the past. Yet when she first learned this history, she’d been livid. She wanted to break free of the desperate conditions her kind found themselves in, no matter what it took. This desire swelled within her until it became delusions of grandeur — she was convinced only she could change the world, only she could save it. She needed power to be this savior. She had to become the ultimate seiyuu. But Akane had not been born a Legend Class seiyuu, and so no matter how much she practiced, there was a limit to her ability.
When Akane learned of this limit, she spent some time as a prisoner of despair. However, by changing her approach, she got it together again. Rather than use her own laryngeal sac exclusively, she began borrowing sacs from other seiyuu, transplanting them to herself. For that purpose, she had killed ten other seiyuu. It had been a tough decision, but now each of them was a part of her — Akane Yomokura, the savior, the ultimate seiyuu. She was sure their deaths had been repaid, and their souls lay at rest.
And today, Akane had stolen Hinagiku Nakayama’s laryngeal sac. It was her eleventh victim. Akane’s body would only allow one more transplanted sac. She had been searching for the strongest one she could, certain that it was her duty to make that sac a part of her own body.