User blog comment:Imouto-tan/Mitsuari Sirens/@comment-4867780-20170511102439

An elite organization of super-skilled operatives specialized in deception/manipulation/assassination, under the direct command of none other that the fearsome Nayuta Mitsuari ? Now, that's one scary thought ^ ^;

The "raised as sisters and forced to kill each other to destroy their emotions" part is a hell of a downer though, makes you want to disband the sirens, have them sent to intense psychological cares for the next decade, and Genryusai publicly skinned alive and scorched on a pyre for the example.