Chapter 0

The master spy Twilight receives Operation Strix, an assignment to dig up the war schemes of Donovan Desmond, a dangerous figure in an enemy state. The catch is that it requires something no lone agent keeps on hand: a wife and child, plus enrollment at a prestigious school. Adopting the identity of psychiatrist Loid Forger, he visits a shady orphanage and selects Anya, its brightest resident, never suspecting that the girl reads minds and is thrilled to learn exactly what her new father does for a living. A meeting with Yor, a woman anxious about the social cost of staying single, produces a marriage of mutual convenience; she quietly celebrates finding a nice man, certain her secret work as a deadly assassin would otherwise rule out matrimony forever. Each member conceals their true nature from the others, and after pledging to prepare together for Anya's entrance exam, the improvised family heads out for a walk, sharing a laugh.

Twilight is handed Operation Strix and constructs the Loid Forger persona.

Anya is adopted and immediately learns her adoptive father's profession through telepathy.

Loid and Yor agree to a sham marriage serving both their hidden agendas.

The prototype Forger household forms and turns its attention to the school entrance exam.

This preview ran in issue 17 of Weekly Shonen Jump in 2019 to promote the manga's first chapter, which launched the same day on Shonen Jump+. Its events sit outside the main continuity, yet all five of its characters were appearing for the first time here, and the series proper retells the family's formation in far greater detail across its opening chapters.