Kamigoroshi-hime Zilch

Haunted by the untimely deaths of his mother, little sister, and a childhood friend, listless high schooler Haruomi Io has trouble engaging with anything or anyone. Of course, that doesn't mean others have trouble engaging with him—a fact he discovers to his dismay when he finds himself the target of a trigger-happy group calling themselves the "Seventh Gospel Organization." Having newfound enemies may be rough, but Haruomi's unexpected ally in the form of a demoness calling herself Zilch may turn out to be even more of a handful...

(Source: Yen Press)