Both Chiaki and Ororon have been ostracized from their respective celestial realms EChiaki because she is an impure angel and Ororon because he is the youngest son of the Lord Devil and therefore a threat to his older brothers for leadership of the underworld.
As various demons come by to eat the angel Chiaki, she learns that having the incredibly powerful Ororon by her side is useful. However the difference between angel and devil becomes clear when Chiaki has to implore Ororon not to kill those that come to threaten them.
Meanwhile, Chiaki's household grows even more when she invites Lady Miss Lucy, the demon cats Shiro and Kuro, her friend Rika, and Ororon's brother Osero to come live with her as well.
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