The experimental site name is "Recoil Play."

Each subject is assigned a class:

Class A is a rare class with fewer than 10 individuals total. They are extremely strong overall, with some boasting strength that exceeds the staff. Furthermore, those who meet these conditions:

1. Remain calm at all times
2. Have never gone berserk
3. Are communicative and intelligent

Class A subjects who fit these criteria may work as staff (and are treated with great preference). Guest is Class A and meets all conditions, thus being exempt from most experiments.

Class B: Inferior to A, but still rare with fewer than 100 individuals total. Strength varies, and not every single one is necessarily strong (some are just barely Class B).

Class C: Composed of those with ferocious personalities who are not strong enough to be a threat. Generally, a license (staff) is required to enter here, and the possibility of death begins to emerge.

Class D: Safe unless harmed. They are either kind-hearted or weak, but many subjects are kind-hearted even if they are in the weak category. The possibility of death is extremely low, and they generally don't even get injured (they are actually healed instead).

Class E: Safe and secure subjects who don't get angry no matter what is done to them. Most are either too kind-hearted or have extremely weak magical power; visitors (civilians) are allowed to enter.

Those below Class A are fitted with electric shock collars. Class A subjects are so strong that control via electric shock is impossible.

The experiments are broadly divided into...

Drug Administration Department, Mechanical Operation Department, and Biological Modification Department. They involve at least some degree of pain.

Drug Administration: Enhancement of magic through administration, or drawing large amounts of blood for staff training to acquire magical power.

Mechanical Operation: Checking pain tolerance via electric shocks (done once for newcomers), checking biological reactions (heart rate, blood volume, body fluid components, etc.).

Biological Modification: Based on DNA analysis, growing wings or horns, etc. Also, occasionally creating clones.