Fire polka

ファイアーポルカ(Fire Polka) is an anime Japanese parody of Hatsune Miku's song Ievan Polkka.

What is ファイアーポルカ(Fire Polka) all 'bout
ファイアーポルカ or Fire Polka is about the end of season 2. But cancelled because it was 15-37 seconds long.This song was now used as a song of montages in previous 20 episode.