Anna cares for two foster children, Yoji and Kei, within a near-future town. She provides them with a home, fostering an ordinary family life under one roof. Unbeknownst to Anna, the children harbor a significant secret: they operate as superheroes defending the town. Yoji and Kei, aided by their robot bear companion Oscar, utilize handmade high-tech machinery to protect citizens, maintaining this double life hidden from their unsuspecting foster mother. Anna remains unaware of their heroic activities and the dangers they confront. When crises threaten the town's peace, the children face these challenges while Anna continues providing a stable home environment, her role focused solely on this domestic stability. The available material does not elaborate on Anna's background prior to fostering the children or her specific personal history. Her development in additional media, such as spin-offs or extended narratives, is not documented.