Sabo Forger, who works under the codename 'Twilight', is now in the country of Ostania, to work for the mission: Operation Strix, to restore the peace between 2 countries. But for the same, he was advised to make a family, and like that, he adopted a girl named Ryah, who has telepathic powers he didn't knew about and now, met a woman, who is an assassin in disguise, which he didn't knew about and thought of making a fake family of three, each of them hiding their own identity from each other.