Hidomi Hibajiri is a disillusioned young woman who never removes her headphones. Her entire existence revolves on attending to school, assisting at her mother's cafe, and listening to music. And, with nothing else to distract her from the agonizing repetition, she wears her headphones at all times. That is, until she gets ran over by a weird woman with a guitar. The same night, a robot bursts into Hidomi's room, accompanied by a boy from her class, Ko Ide, and the two are hunted about town together. They're rescued by the woman with the guitar from before, but now Hidomi has a horn sprouting from her forehead? Who knows where these robots are coming from or what type of vespa woman this strange guitar lady is warning her about.