Top 10 in Top 15 best yuri anime.
Akuma No Riddle trailer
A student and assassin, transferred to Myoujou Academy under the name Tokaku Azuma along with 11 other skilled assassins, they are tasked with killing a girl named Haru Ichinose. The point is, they'll only get 1 chance, and if they fail, they'll be kicked out. And if successful, all their ambitions will be fulfilled. Despite being rather cold and trying to avoid growing feelings towards her goal, Haru. Tokaku's admiration for Haru is tested, and instead of killing Haru, Tokaku decides to protect her from other assassins.