Who would have thought that an ordinary human girl had Satan himself as her guardian angel!? Mimiko, a 19 year old girl who was orphaned, did nothing but play her beloved piano at the devil's hour and has now been sent to the Heavens where she then get's thrown into Gehenna and is forced to serve Satan, the strongest fallen angel who was kicked out of the Heaven's for accidentally killing a god! But who would have guessed that fate was what brought them together? A tale of the decadent romance between a handsome fallen angel and a human awaits your eyes!