Two children who got swapped at birth grow up to become engaged to each other. It's an arrangement neither of them like, at first.

Touka Kuroitsu 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.

Nene and the ghost of Hanako-kun want to stay out of trouble at Kamome Academy, but shenanigans follow them wherever they go.

Living in the lawless Ishinari District in a future Japan, sisters Ami (Hina Nagimiya) and Yoshie (Hanakage Kanon) who sold their bodies to help their parents, try to earn a living performing as an idol group in the area. When their performance causes stranger Matsukata (Tak Sakaguchi) a notorious hitman, to notice their condition, the three realize their worth to each other in the fight against Aoyama Dharma (Kimono Negishi), the female boss of a notorious organ harvesting ring in the area. Realizing that even their skills are no match for her army of goons and henchmen, the two are outfitted with special homemade weaponry to their bodies and become the ultimate killers.