Sin: Nanatsu no Taizai

 Every once in a while, one can have some guilty pleasure and watch an ecchi anime, and this time it was The Seven Mortal Sins.

And it had a lot of guilty pleasure gnih gnih gnih...

The anime is a take on the biblical story of how Lucifer was cast down from Heaven into Hell, where she plans to become to overlord, replacing Belial, and take her revenge on Michael.  Halfway on her plummet though, she gets stuck on Earth meeting and enslaving a girl named Maria.

Upon her arrival in Hell, she meets fangirl Leviathan and together they set out to overthrow the Seven Mortal Sins, but as they combine their powers they overcome Lucifer and place the Garb of Punishment on her, transforming her into a Demon Lord.

But one by one she overcomes the Sins, reducing the grip of the garment and uncovering a plot by Belial to sell out Hell in order for her to reascend to Heaven herself...

An okay series, with of course a LOT of very buxom fanservice, but heck, it was fun to watch and some decent laughs where let out.