Hitoshiki's older brother, master of the giant scissors, discovers a just awakened Zerozaki -- a 17 year old girl named Mutou Iori. Before he can convince her that his offer to make her his sister is not creepy and sinister, she gets mixed up in a bloody conflict with a pair of furious killers out to avenge their sister's death.

Manga is based on Nishio Ishin's novel “Zerozaki Soushiki's Humanity Test”. Story and art handled by Shiomiya Iruka.