The story takes place in the future, and it begins with Kei and Ai fleeing for their lives. Ai is a little girl with a dreadful secret that threatens to destroy the current world. Headmeters, persons with psychic abilities whose strength is displayed on their forehead as they battle, have taken over the planet. However, Kei was an experiment subject, and his strength never exceeded level 5, despite the fact that others easily outperform him. When Kei was escaping and in a difficult situation, he could enhance his ability to infinite. The assailant has a dark secret and is supported by a little dwarflike man in a robotic suit. Ai is eventually apprehended by Kei, a Sherlock Holmes detective.