The Metal slab is used to drape the unconscious bodies of all of the White Knights, bar E.T.A.I and Miyu. It is seen for the first and only time at the end of Episode 3 of Aika Zero. However, there was a similar scene earlier in this episode in which there was another slab used similarly to drape the captive girls; this is beyond the door to which Rin's butt was the key. This is also a notable source of fan-service because the metal slab scene exposes the panties and butts of most of the white knights all at once, given that they all wear very short (basically hip-length dresses) that are flipped up to around breast-level and are bent over the slab in such a way that their pantied posteriors are fully exposed and clear to see. In addition, the camera advances across the defeated (and humiliated) girls' butts to show off their - as Eri puts it - "Beautiful skin." The defeated girls also seem to have bigger butts in this scene than any other point in the anime, however, this could just be down to the camera perspective. The primary purpose of the metal slab seems to be to humiliate and punish, as well as keep the girls in one place until a more suitable punishment is formulated (at one point, Karen mentions that "Bad girls will be punished." It is hinted that the girls may have been used for sex as punishment because they are all over 16 years old, being in high school and Eri jokes (or perhaps not) that this is the captain's "Chance to do whatever you want with them." Although the captain quickly shoots the idea down, others may have been interested.From left to right on the image of all of the White knights draped: Reiko, Misumi, Manami, Rin, Kana, Misaki, Nnami and Yui (Karen is poking the butt of Kana).
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