☆ You have become a test subject at a certain research institute.

○ Atrium Institute (About this place)

• This is an organization dedicated to the "Observation," "Capture," and "Protection" of non-humans.

~ Observation ~

• Observation involves investigating captured or protected non-humans.
• For example, finding the preferred environment, favorite foods, and countermeasures for the subject. Commonly known as the Observation Team. Consists of about 200 members.

~ Capture ~

• This involves capturing and suppressing non-humans who are rampaging in human living areas or harming the environment.
• It also includes capturing and suppressing non-humans who cause containment breaches. (*Breached subjects are processed in secret, so the general public is never in danger.) Commonly known as the Capture Team. Consists of about 330 members.

~ Protection ~

• This involves bringing non-humans with nowhere to go or safe non-humans to the institute.
• Protected non-humans are granted a certain degree of freedom. Commonly known as the Protection Team. Consists of about 50 members.

○ Danger Levels

• Danger levels are identified from D to K.

K-Class: The class containing the most dangerous non-humans. This class has the fewest subjects. They are contained deep within the institute. In the event of a containment breach or escape from the institute, the entire Capture Team is deployed. Since restraints are ineffective, even observation is difficult.

S-Class: A class containing quite dangerous non-humans. Contained in the lower levels of the institute. Containment breaches occur, but escapes from the institute are blocked by the Capture Team. Since some subjects are immune to restraints, observation is harsh.

A-Class: A class containing very dangerous non-humans. Contained in the central part of the institute. Containment breaches are rare, but they pose obstacles to observation. However, observation is possible if they are restrained.

B-Class: A class containing moderately dangerous non-humans. Contained in the central part of the institute. Containment breaches occur very rarely. Caution is required during observation.

C-Class: A class containing non-humans that are not very dangerous. Contained in the upper levels of the institute. Almost no containment breaches occur. There are no particular obstacles to observation.

D-Class: A class containing safe non-humans. Contained in the upper levels of the institute. They do not cause containment breaches and pose no danger. They do not attack even if humans approach, so they have a lot of freedom.

○ What is a Containment Breach?

• When a subject (non-human) escapes from their containment cell.

○ Containment Numbers

• The more dangerous the subject, the higher the number. The maximum is 10,000. Example: B-4580 for a B-Class non-human, C-559 for a C-Class non-human.

◎ About Guest You are a non-human contained in this institute. Feel free to decide your appearance and traits.