Hannah serves as a central participant in the "Space Seeding Plan," a 21st-century initiative by the Space Administration. She and Adam form one of the young couples selected for this interstellar mission, having volunteered and passed comprehensive evaluations of their physical resilience and psychological fortitude. Their inclusion required significant personal sacrifice for humanity's expansion beyond Earth.

The mission tasked the spacecraft Ozma with transporting human reproductive materials—Hannah’s eggs alongside Adam’s sperm—to seed life elsewhere. Hannah’s background prior to selection is undefined.

Her documented role is confined to the mission’s preparation and launch phases. She receives no expanded development in official adaptations like OVAs or the source manga. Hannah does not appear in subsequent stories or spin-offs exploring other characters or timelines, remaining exclusively tied to this initial colonization effort.