"We all have a side we don't want to show to others." This is the age when all the countries of the world are involved in an intense information war behind the scenes.

The eastern country of Ostania and the western country of Westalis were in a cold war for more than a decade. Agent "Twilight" or "Twilight" is a skilled spy working under the auspices of the Western Intelligence Service for the Eastern Region, WISE. Senja is assigned to carry out a high-class secret mission to investigate the war plans of a dangerous man who threatens peace between the East and West countries who has the position of President of the United East Party named Donovan Desmond.

The name of this mission is Operation Strix. This mission begins by starting a family in the space of one week and infiltrating the prestigious school where Desmond's son is studying. However, the "princess" he meets on a mission is an esper who can read minds.

Meanwhile his "wife" is a murderer! The three of them become a family and live together while hiding their true identities to maintain mutualism between them.