From Surgipelago, the Beach Surgery encyclopedia
Leif#Backstory
This article addresses the backstory of Leif, the military engineer. For his role in Beach Surgery (story), see Leif. For Katita's account of this period, see Katita.
Leif's origin is established in the novel's frame narrative: he is a military engineer stationed near an unnamed beachfront in a conflict zone. During humanitarian evacuation, a refugee child is caught in tidal currents; Leif dives from a high breakwall to retrieve the boy and is smashed unconscious against rocks.
Katita, working as field triage nurse, resuscitates him. This moment—the first surgery—is where she decides: “Leif is her tool of change.” She has "fashioned his love in the most surgically strategic of ways." She evacuates him to Australia and drives him to her makeshift facility in the interior.
What Leif consciously remembers remains ambiguous; adaptations diverge sharply. Some versions propose complete amnesia of the beach rescue. Others suggest fragmented recall of the boy but not Katita. The manga expands the backstory extensively, proposing the boy as Katita's lost sibling. The TV series redates events by decades. [citation needed]
The glitch between Half One and Half Two is partly a glitch in Leif's own consciousness: he cannot integrate the rescue with his present state.