This is the extended version of the anime song from the series:
Deca Dence
没落要塞
デカダンス
animeanime songanime song extendeddeca dence opdeca dence op extendeddeca dence op fulldeca dence op full extendeddeca dence ostdeca dence ost extendedDECA-DENCEextended anime songextended deca dence ostextended Konomi Suzuki songskonomi suzukiKonomi Suzuki songsKonomi Suzuki songs extendedTheater of Lifetheater of life extendedデカダンス
MAG.MOE - The MAG, The MOE.