Riddle Story of Devil

Akuma no Riddle is manga series written by KOUGA Yun and illustrated by MINAKATA Sunao.

Plot
At a boarding girls' high school for trained assassins, one group;the black class,they target only one person -"Ichinose Haru". "Azuma Tokaku" is an assassin who transferred schools for a specific reason and is told to assassinate Haru,however she decided to protect her. Extreme school life, START!