Devil's Riddle) is a Japanese manga series written by Yun Kōga and illustrated by Sunao Minakata.

It was serialized in Kadokawa Shoten's Newtype magazine between the September 2012 and November 2016 issues and is licensed in English by Seven Seas Entertainment.

The original title is a pun on Devil's Trill (悪魔のトリル, Akuma no Toriru) by Giuseppe Tartini.

[9][10] An anime adaptation directed by Keizō Kusakawa and produced by Diomedéa aired in Japan between April 3, 2014, and June 19, 2014.

Episode 12 contains an insert song titled "Aogeba Tōtoshi" (仰げば尊し) sung by the main thirteen voice actresses.

With all the other assassins returning to their regular lives, Tokaku sends one last reply to Kaiba before joining Haru in delivering everyone's diplomas.