Doppeliner (Doppeliner System).Keita Ibuki is currently a high school student living alone in Tokyo while being assisted by his father, who remits money for his allowance, and daily visits by his old childhood friend Akane Sano after his mother dies from an encounter with her own Doppeliner as a young boy. After seeing the spitting image of someone with the same looks as his own mother, Keita visits a ramen shop when Kuro shows up with her pet dog Punipuni. After Kuro receives her ramen from Keita, she is severely attacked by an unknown assailant who was ordered to capture Kuro alive at all costs, despite Keita trying to stop him. He later meets with one of his neighbors, a young girl named Mayu, only to watch a speeding truck run her over after she claims that she had met her double.