Contrary to popular belief, it is not a shojo manga. (It doesn't even have that much romance.)
It has way more action and is far too in depth. It has some of the best art seen in manga in a LONG time.
Taking place in 1920's America it's about an exorcist named Rosette Christopher. She has contracted with a demon named Chrono to have her soul drained so he can use his powers and help her find her missing brother, Joshua. It is unlike any other manga out there. Really, read it.
The anime sucks. (and the dub is horrible, never watch it.)
person B: Sorry, I was too busy watching Inu-Yasha.
person A: ...You're dead to me.
(yeah, Inu-Yasha is disgusting. Absolutely nothing compared to Chrono Crusade.)
person 1: Oh my god! What happened?
person 2: Oh, their head just exploded.
person 1: Why?
person 2: They read the last volume of Chrono Crusade. It was so amazing it made their head explode.
person 1: ah.