Touka Kuroizu is a research assistant who belongs to the Monster Development Department of the evil organization Agastia. However, the enemy she has to fight right now isn't the heroes of justice, but her boss. So long justice exists, evil too, will exist. This is the story of those who fight secretly in the shadows of justice and evil's confrontation.

 HiddenLeaf is the best site to watch Kaijin Kaihatsu-bu no Kuroitsu-san SUB and DUB in HD quality.