At Myoujou Academy's "Class Black," students are trained for assassination. The class appears normal but serves one purpose - to eliminate the target student while the others act as assassins. If an assassin successfully kills their target, they can have any wish granted, but only one chance is given; expulsion awaits those who fail. Azuma Tokaku, a disinterested assassin-in-training, gets transferred to Class Black with 12 other girls. Among them, Haru Ichinose stands out - she's cheerful and determined to make friends and graduate. It turns out that Haru is the target, prompting the students to plan her assassination. However, Azuma develops feelings for Haru and decides to take a different path. For the first time in her life, she finds a reason to fight for something.
Akuma no Riddle has been published digitally in English by Kadokawa Bookwalker since October 29, 2014. Seven Seas Entertainment physically released the series from October 27, 2015 to August 15, 2017. It has also been published in Spanish by Ivrea España and Ivrea Argentina.