Apparently Japan had never won the World Cosplay Summit before this year [1]. Congratulations to the winners YuRi and RiE, who won with a Sengoku Basara (戦国BASARA, or Devil Kings) cosplay.
The above picture is of special guest performers SKE48, an offshoot of the band AKB48. SKE48 is based in SaKaE in Nagoya, whereas AKB48 is based in AKihaBara. Both bands are incredibly cute.
Video of both bands is below - Who do you like better?
SKE:
AKB:
More pictures from the Cosplay Summit can be found here.