Zupa

A young hermit girl who lives on the outer wall of the Vertical World, who joins Ruska and co. after a sudden encounter.
Despite her age, she is an extremely proficient mechanic and computer hacker, whose skillset proves invaluable to the party during their journey through the Vertical World.

It is later on revealed that Zupa is not human, and is in fact a robot that happens to be a physical manifestation of a "virus" unleashed on the Vertical World by Professor Laniakea. Explaining her almost-supernatural ability to construct fantastical contraptions and cybernetics on such short notice. As well as her uncoventional dietary preference for the mechanical floating eyeballs that surround the Vertical World.