For those who doesn't understand, this is a parody of Kasou Taisou('Masquerade' in some countries), a japanese TV show where the contestants makes short skits to mimic something(be it waves, cutting motion, racing, etc). Probably because 仮装(costume) is spelled 'kasou'. And here we have Koishi as both the MC and contestant, with Flandre, Nue, and Meiling as judges.
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PichuuuunSo it's that onee!!!One-man Staffshwoosh shwooshWell~
That's too bad~But now is your end!!BOOM (spellcard sound)