Its about a guy who can see people true names and then in the manga people that get their true names found out becomes submissive and mostly only their parents know. This guy knows the true name of two girls in an exorcism clan, the girls are cousins and one got a strict mother. The exorcism in this manga is carried out by finding out the monster's true name.

sounds interesting. I hope someone knows this...

Isuca maybe?

"You shouldn't choose your path by your sins, Instead you should carry your sins depending on the path that you chose"