Setting: Started with old China/Japan place, then to modern world
It starts with some angel/heaven girl from the heaven was born in the world, along with her were a bunch of guardians. People says who eat her heart will be immortal so her family was killed in a fire. There was one servant that's about her age so he took her running away from the killers. Then they found the rest of the guardians and fought a final boss fight where they killed the evil witch person. But the heaven girl person died too. The witch cursed the girl that she will be back again a 1000 years later to kill the girl, then proceeded to blow up the place. The main guardian guy (the servant) threw some guy out and told him to use spells and so all of the guardians will reborn to protect the heaven girl once again.
Modern days, this one lazy and stupid guy suddenly learns from his foster father that he is this one awesome warrior and they will protect this one girl from evil force. The girl turns out is this one clumsy girl who caused the guy to do some stupid stuffs. Blah blah..the evil force returns, people died, the guardians gather once again, and the heaven girl's heart got eaten. They fight another final battle and everyone died except this one girl guardian.
Final scene, couple years later, the guardian girl becomes a cop. Once day she see two kids, a girl saving this boy from bullying.
Tada. Please if someone remembers this series, do tell me the name. I'm looking for it for a very long time. Thank.
________________
An instant or an eternity. Both are the same, in the passing of an instant lies the beauty of eternity.
-Ginen Shounen
"It is now time to leave-for me to die, and for you to live-though which of us has the better destiny is unclear to everyone, save only to God."
- Plato
YAY! That's the one I been looking for. Thank you very much. 
