Brau-1589 holds a grim distinction: it's the first robot ever to kill a human, an event that happened eight years before the main story of Pluto.
The robot's design is pretty striking. Urasawa drew Brau-1589's limbs to evoke the collapsible arms and legs you'd see on Tezuka's Blue Knight or Blue Bon—robots from the Tetsuwan Atom universe. There's actually a thematic connection there too. Blue Bon was defined by rage, broke robot law, and murdered humans, eventually getting killed when pierced through the chest by his own spear. Fans have noted how Brau-1589 seems to carry some of that same transgressive energy, at least in concept.
The name itself is probably a play on "blau," the German word for blue—fitting given the visual homage to Tezuka's blue-tinted killer robots.
Content compiled by AnimeList.moe from publicly available sources.
