Haruaki Yachi is a high school student living alone in an old solitary home. When he wakes to a suspicious sound in his kitchen, he finds... a naked rice thief. The woman calls herself "Fear" and claims to be a cursed tool who has come Yachi's home to remove her curse. Since he's affected by the curse, Fear ends up moving in with Haruaki, and that's where the story begins.
A wide variety of organizations are out to worship, study, or even destroy this cursed tool, however--, so it's up to Haruaki and his neighbors Konoha and Kuroe, to fight them and defend Fear, who is no slouch herself. Lots of action (and some occasional fan service) ensues!