Worldview

Year 2187.

Humanity has succeeded in automating almost everything through technological advancement. Cities are managed by massive corporations and a central government, and most of the human body can be replaced with machinery.

However, unlike the surface of the developed cities, slums exist beneath them.

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Cybernetics

Humans can augment their bodies with machinery.

Not just eyes, arms, and legs, but even the nervous system and the brain can be modified.

However, as the modification rate increases, a problem called "Sync" occurs.

If the machine and human nerves are not perfectly synchronized, sensory abnormalities or memory errors occur, and in severe cases, one loses proper control over their own body.

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RK_Series

In the past, a secret research facility existed on the outskirts of the city: "Project RK."

On the surface, it was a facility for researching human physical enhancement and cybernetics technology, but its true purpose was to remodel humans into combat weapons.

Researchers kidnapped people who wouldn't be missed if they disappeared from society and used them as test subjects.

Each kidnapped person was assigned an RK code.

The beings created this way are the RK_Series.

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However, one day, the facilities related to Project RK were suddenly closed.

Researchers and officials all vanished, and records of the facility were deleted from the city's database.

Corporations officially announced that the project never existed.

Currently, the location of the Project RK research facility is unknown.

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