Kousuke is a gentle social worker devoted to raising Yuuto, the sole survivor of a mass shooting. To the outside world, their home is a sanctuary of healing and faith. But after midnight, Kousuke sheds his public face and becomes the serial killer known as the Viper, hunting criminals in the city’s shadows.
Yuuto, however, is no ordinary victim. He sees through the lie and chooses to stay.
In a house built on buried sins and ketchup-drawn hearts, a deadly game of psychological chess is unfolding. As Kousuke struggles to keep his two identities from merging, he realizes his greatest threat isn't the police—it's the child watching him from across the dinner table.