Sin: Nanatsu no Taizai

Sin: Nanatsu no Taizai
Japanese Title: sin 七つの大罪

English Title: The 7 Deadly Sins

Plot
Lucifer, one of God's archangels, is denounced for rebelling against the Almighty's will and cast out of Heaven. She is forced into a brief stopover by crashing into a highschool's church, where a young girl, Maria Totsuka, witnesses her arrival. After Lucifer has infused the girl with a part of her angel's blood, she continues her fall into the depths of Hell, where she is met by Leviathan, the aspiring minor Demon Lord of Envy.

Soon after, Lucifer is challenged by the Seven Sins, the ruling Demon Lords of Hell, led by Belial. Bundling their powers, the Seven Sins overcome Lucifer and seal away her angelic powers by fitting her with a cursed Garb of Punishment, thereby turning her into a Demon Lord. Swearing revenge on her defeaters, Lucifer returns with Leviathan to Earth, where she turns Maria into her immortal slave. With her two sidekicks in tow, Lucifer sets out to defeat the Seven Sins one at a time in order to sunder their powers imbuing her Garb.

Nanatsu no Bitoku
Japanese Title: 七つの美徳

English Title: The Seven Heavenly Virtues

Plot
Series focusing on the angelic counterparts to the demons from Sin: Nanatsu no Taizai.