Totsuka Maria was praying in a chapel at Seiseki Girls' Academy when a black cross comes falling from the sky. On that cross, was a fallen angel, bearing the sin of pride, Lucifer. Maria attempt to tend to the angel, but the floor falls out and she disappears. Lucifer finds herself in the depths of hell, and runs into the Demon Lord of Envy, Leviathan.
But if there are angels,
would that mean there are demons, too?
Aber wenn es Engel gibt, dann müsste
es doch auch Dämonen geben.
Pero si hubiera ángeles,
también habría demonios, ¿no?
Pero si hubiera ángeles,
también habría demonios, ¿no?
Mais si les anges existent,
ça signifie que les démons aussi, non ?
Però se esistono gli angeli deve significare
che esistono anche i demoni, no?
Mas se anjos existirem, então 
demônios também existem, não?
Но знаешь! 
Если ангелы существуют, значит, есть и демоны.