Hana Yamada, a high school girl, gets sick after drinking alcohol during a mixer, and is rescued by a very cool guy who she thinks is a student. However, when he suddenly asks her if she's a elementary school student, Hana becomes very angry and kicks him, before running away. The next day, when Hana goes to the nurse's office, she finds none other than the very boy who'd made her angry, Shuuji Kidou...
(Source: Midnight Scans)

He's perverted, malicious, a devil that calls himself 'Ore-sama'.
His true character is -? The Demon King, Char, from a parallel world called Avalon, fell in love with the daughter of a shrine, Hashiba Rin. Both their hearts and bodies have been entrusted to each other, but a first love, Shou-chan, confesses to Rin-?

Hashiba Suzu lives together with her grandpa. One day, while she was praying to the gods at a shrine, a devil calling himself Char appeared. Char who seeks the "blood of a virgin" is perverted, ill-tempered, and pompous. He isn't very straightforward, but the truth is that his kind touch is full of love, and while knowing an unforgivable a love before he knew it, his heart and body grew weak...