Riddle Story of Devil

Tokaku Azuma, an assassin in her tenth year of school, gets transferred into Class Black and must find a target among her classmates to eliminate; she meets potential target Haru Ichinose, a kind girl who turns out to be her roommate.

All 13 students of Class Black assemble and things get serious when one of them thinks she can jump the gun and beat everyone to the prize.

Tokaku switches sides to protect Haru, but the game continues and a student makes the first official assassination attempt.

In three straight days of testing for Class Black, Haru focuses intensely to pass the tests while another one of the girls gets a shot at killing her.

Class Black prepares to put on a production of "Romeo and Juliet" for the school festival and another assassin tries her luck.

Class Black puts on "Romeo and Juliet" in front of a student audience, but with so many deaths in the play, an assassin bets she can manage a real one.