Rin Okumura, diagnosed with Antisocial Personality Disorder (ASPD) at age of 12, well diagnosed by human standards. (I've read a few things saying that it'd be diagnosed at 18 but its for the sake of the story line of Rin being 15). When Rin's adoptive father, Shiro Fujimoto dies due to his biological father Satan, an...
In a fit of rage, five year old Okumura Rin unlocked his secondary powers, and felt as if he was forced to flee because of it. While sitting in a cemetery tree, a man who claims he's Astaroth tells Rin his real father wants to meet him. Feeling helpless, Rin agreed to go with the man, and so his life in Gehenna begins.
[So in the story Rin has known all his life that he has demon powers and has known that Yukio was an exorcist.Also Rin didn't unsheathe his sword so no powers yet.And the story takes place two months after Shiro has died and it is after the exwire exam so Amimon isn't in the story yet] So in this story things are very...