Riddle Story of Devil: Who's the Winner?

Riddle Story of Devil: Who's the Winner? is the unaired thirteenth episode of Riddle Story of Devil (Akuma no Riddle), released with the seventh Blu-ray and DVD volume of the series.

The main series takes place at Myojo Academy, an all-girls boarding school where Class Black is far from an ordinary class. Twelve of its thirteen students are assassins, and all of them are after the same target: Haru Ichinose, a cheerful and seemingly ordinary girl. Whoever manages to kill her within the allotted time will receive a reward of their choosing. The only student who stands in their way is Tokaku Azuma, a cold, highly skilled assassin from a renowned family, who unexpectedly decides to betray her mission and protect Haru instead, facing one opponent after another as the classmates make their moves.

This extra episode returns to the girls of Class Black, offering fans one more outing with the assassins, Tokaku and Haru after the conclusion of the television broadcast.