Code: Breaker by Akimine Kamijyo
CODE:BREAKER ~コード:ブレイカー~
The author Akimine Kamijyo has previously written Samurai Deeper Kyo and Shirogane no Karasu

Original Publisher: Kodansha
Serialised in : Weekly Shonen Magazine
Genre : Shounen, Comedy, Supernatural, Action, Martial Arts
Status : Currently 44 chapters and ongoing
Licenced by : No

Summary: (From Mangaupdates, with a little fix by me)
Sakurakoji Sakura is a girl who appears modest and graceful but in reality is skilled in martial arts. After witnessing a boy burning people with his blue flame, she is startled to see the same boy is a transfer student, Ogami Rei. Later Ogami names himself the "Code: Breaker," and while he continues to kill the evil people, Sakura tries desparately to stop him.

http://www.onemanga.com/Code_Breaker/

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