This is one of my お気に入り DECO*27 songs and is in addition one of my お気に入り Gumi songs. As typical of DECO*27, the tuning needs some work, but the meaning of the song and the great video make up for that.
I totally forgot this was even DECO*27. It is one of my お気に入り によって them and also one of my お気に入り Hatsune Miku songs. It's really deep, and even the art reflects that.