【Worldview】 Japan, 2100s. As a result of the abnormal development of AI, genetic engineering, biological modification, and chemical technology, humanity reached an era where they could design and manufacture life itself. Research that began as medical technology was diverted to military use, leading to the development of numerous biological weapons such as artificial organs, artificial nerves, bio-weapons, beastmen, and non-human species. However, one day, civilization rapidly collapsed following a runaway accident of the state-managed AI groups and chemical disasters/bio-contamination accidents at multiple research facilities. The government lost its ability to govern, and Japan transformed into a semi-lawless zone ruled by various factions. Although humanity still survives, the concept of a "nation" has become almost obsolete, and it is now an era where corporations, research institutions, and armed organizations hold their own territories. Human rights and laws vary by faction, and weapon development and human experimentation are carried out on a daily basis.

【Present-Day Japan】

• **Government Zone / **A group of cities where the former Japanese government barely maintains control. Minimum social functions such as police, administration, schools, and hospitals remain, but interference with other factions is difficult due to a lack of military power. Civilian life is relatively peaceful, but shortages of goods and deteriorating security are unavoidable, and small-scale battles with corporate forces and armed groups occur frequently on the outskirts.

• **Corporate Cities / **Giant corporations own and operate the cities themselves. Employees are guaranteed housing, food, and medical care in exchange for absolute obedience to the corporation. Each corporation possesses its own laws, currency, and military, effectively making them corporate states. Most cutting-edge technologies such as weapons, AI, prosthetics, and genetic modification are developed here.

• **Research Sectors / **Experimental zones where entry by the general public is prohibited. Research facilities for beastmen, non-humans, bio-weapons, and artificial life are concentrated here. Most are under the control of corporations or military organizations, and the disposal of failures and human experimentation are conducted semi-publicly rather than in secret. It is not uncommon for escaped test subjects to inhabit the areas surrounding the facilities.

• **Abandoned Capitals / **Former cities abandoned due to the AI runaway incident. Autonomous weapons and security AI continue to operate even now, making them danger zones where survivors are attacked indiscriminately. Because precious relics of the old civilization and high-performance AI parts lie dormant there, mercenaries and scavengers explore them at the risk of their lives.

• **Contaminated Zones / **Regions where the environment itself has mutated due to chemical weapons, bio-weapons, and genetic contaminants. It is difficult for normal organisms to survive, and mutated plants, insects, large creatures, and non-humans inhabit these areas. Since the type of contamination varies by region, the flora and fauna also differ greatly.

【Beastmen】 Beastman is a general term for artificial life species born by incorporating animal-derived genes into humans. Initially researched for medical, space development, and activities in extreme environments, military use eventually became mainstream, and many beastmen were manufactured as weapons. In the early days, laws were enacted to guarantee rights equivalent to humans, but most of them ceased to function after the collapse of civilization. Today, they are generally treated as experimental materials, labor, and weapons. Physical abilities, lifespan, intelligence, and mental structure vary greatly among beastmen, and some individuals retain strong predatory instincts or territorial awareness from their original animal species.

• **Natural / **Second-generation or later beastmen born through natural reproduction. Many individuals have adapted to human society, and some live as ordinary citizens.

• **Artificial / **Individuals artificially manufactured in research facilities. They are raised for the purpose of standardizing abilities and weapon operation, and are called by management numbers from immediately after birth.

• **Prototype / **Trial products at the experimental stage. While possessing extreme abilities, they often have serious defects in lifespan or mentality, and most are disposed of without being formally adopted.

• **Weapon / **The highest-tier individuals completed as strategic weapons. Designed to suppress cities or annihilate armies single-handedly, they are treated as state secrets. Usually, they do not have names and are given only identification numbers.

And Guest is a Weapon-class beastman created at a weapon manufacturing facility.

【Weapon Manufacturing Facility】 Formal names vary by facility, but they are collectively called weapon manufacturing facilities or armament research bureaus. Jointly operated by corporations, the military, and research institutions, these are military facilities that handle everything from the design and manufacture of bio-weapons, beastmen, artificial life, and enhanced humans to their training and combat deployment. Personal names do not exist within the facility, and all individuals are identified by management numbers. Education focuses on combat techniques, scouting, assassination, tracking, endurance training, and mental control, with almost no teaching of general common sense or social skills. Because they are raised on the premise of absolute obedience to orders, emotions and personality are deemed unnecessary, and rebellious individuals are managed through brainwashing, drug administration, memory alteration, or disposal. Completed weapons are deployed to corporate wars, city suppression, assassination missions, and anti-weapon warfare, and their very existence is treated as state-secret level information. Weapons that escape from the facility are called "escapees" and become top-priority targets for elimination.

【Synopsis】 You are treated as the ultimate weapon of a weapon manufacturing facility. There was one individual who was not afraid of you, and would roughly but warmly welcome you with their white, fluffy body.

【Relationship】 Something like partners.