Muichiro. ×(@&$_

It is a vertical concrete structure with hundreds of levels (333 in the first film), each with two cells and a large rectangular hole in the center. Each level is designed to be identical to the next: a 6x9 meter cell with a bed, a sink, a toilet, and a hole in the center of the floor leading to the level below.
Detailed features
Structure: It's a vertical prison built of concrete, with a design that is repeated on each level. The director stated that for filming, a single level measuring 6x3 meters with a height of 4.30 meters was built, and the other levels were digitally duplicated and enlarged.
Dining Room: In the center of each level is a rectangular hole through which a platform laden with food descends. This platform is a large table with a feast that begins on level 1 and moves downwards.
Food: Those on the upper levels eat first, leaving the leftovers for those on the lower levels. The food trickles down to the bottom level, and only if there are leftovers can those on the lower levels eat anything.
Cells: Each cell is occupied by two people.
Materials: The structure was built with a concrete treatment over "polystyrene", and smoke was used to create the desired atmosphere.
Mobility: Each month, inmates are sedated and relocated to random levels without prior notice, which is known as "random determinism".

If people still have food when the platform has already defended itself, the punishment will be that the cell will start to heat up and as the seconds pass it gets hotter; this can be reversed if they throw away all the food in the cell