One day, Naho Takamiya receives letters that claim to be from herself ten years in the future, each letter describing a different day and what she must do to prevent her "biggest regret". At first, she thought it might just have been a prank but just as the letter described, Naho and her friends befriend the new transfer student named...

Nitta Yoshifumi is a wealthy Yakuza member. One day, a young blue-haired girl with telekinesis powers called "Hina" appears in his apartment out of nowhere in a metallic cocoon. Worried he'd be killed he lets her stay with him. Before long, he learns she must unleash her powers frequently or she will overload and go outofcontrol...