Name of an Anime I can't Remember

[mitchell271]

It's about a boy in high-school who is killed by a demon/alien while defending his sister who is brought back to life by a girl. She and her commanding officer have weapons that come from hexagonal stones or metal with a japanese symbol in the middle. Her CO wears a large white cloak and hat which covers his face.

Can anyone help?

 

[V8 Ninja]

Maybe the anime is called "Kora wa Zombie Desu Ka? [http://en.wikipedia.org/wiki/Kore_wa_Zombie_Desu_ka]"?

EDIT: I'm completely wrong. Look at the comment below mine.

 

[Rokusi666]

Sounds like you're thinking of Buso Renkin.

http://en.wikipedia.org/wiki/Buso_Renkin

 

[mitchell271]

It's Buso Renkin! Thanks so much