Very loosely based on Christian faith. Rin Okumura (15) is the illegitimate son of the Satan. I've no idea why it is even mentioned that Rin is born out of wedlock. If only because the Antichrist is supposed to be a bastard because he denies the Father...? Ok, I have no idea. Rin has a twin brother Yukio who isn't son of the Satan. So it makes them a half-brothers and reminds me of Hercules and his twin brother Iphicles. Very confusing. I like the art, especially main character is nicely drawn and mangaka has thought of every small detail. I'm curious if in the next volume Rin will show some demonic trait and no I'm not talking about tail, teeth and horns.