There are many different girlfriends, the easy going, the needy, the out going, the hard to deal with but still loving, the unusual but cute, the rather possessive, and finally the obsessive girlfriend. But sometimes there are ones that fill every criteria.

Kouta Kogome is a normal japanese high schooler that lives a not so normal life with a not so normal relationship with his girlfriend, Death. In exchange for saving him, he belongs solely to her now. Worse is the fact that she's madly in love with him to the point where if he talks with another girl, she kills him. What makes it even worse is that he can't die due to their intertwined fate, making him an immortal. When strange events happen all around him, all hell will break loose...literally.