Codename "Twilight," a top spy from Westalis, carries out missions to maintain peace and prevent any incident that could spark a war between Westalis and its neighboring country, Ostania. His next assignment requires him to infiltrate the prestigious Eden Academy by posing as a family man, with the goal of gathering information on influential Ostanian politician Donovan Desmond.
Adopting the alias "Loid Forger," Twilight takes in Anya, an orphaned girl who can read minds, to play the role of his six-year-old daughter. For his wife, he selects Yor Briar, an office worker pretending to be in a relationship to satisfy her social circle. Unbeknownst to Loid, Yor is actually the deadly assassin known as "Thorn Princess," and this union provides her with an ideal cover. Anya, unknown to both Loid and Yor, is an esper—the result of secret experiments that gave her telepathic powers.
Despite learning the truth about her new parents, Anya is thrilled that they are both covert operatives. She keeps their secrets, ensuring their charade continues. As "The Forgers," Loid, Yor, and Anya must maintain their facade while pursuing their individual goals. Through their interactions, they come to understand that family can transcend biological connections.