Ai City

In the future, Kei and Ai flee for their lives. Ai is a young girl possessing a dangerous secret that could alter the world. Headmeters, individuals with psychic abilities, display their power levels on their foreheads during combat. Kei, an experimental subject, remains at a low power level, unable to match others. In moments of desperation, especially when Ai is in danger, Kei's strength surges infinitely. Those pursuing Ai are connected to a mysterious secret, assisted by a small, dwarflike figure in a robotic suit. Ai is eventually captured, prompting Kei, a Sherlock Holmes-style detective, and a reformed Headmeter—converted after witnessing Kei's immense power through Ai—to mount a rescue. Their mission is to save Ai and uncover the truth behind her secret.