"Decayed world" is ethnic song of multiple chorus by Len Kagamine. This song is "Genesis","Praying for rain" and "To the forest of ancient - demise of poetry" are made of the same view of the world .
This is the world of the post-1000 from the "Praying for rain". Stupid human beings, overlaying the conflict to seek a slight resources. Bard, while wandering the battlefield, sing that not everyone escape from the "end of day".
キャラクター： Kagamine Len