The man known as Zaurum, bearing the head of an unparalleled treasure that even unsettled bounty hunters at the edge of the universe, once fought fiercely against Emilia on a distant planet and was ultimately captured. His head, believed to hold the key to developing a new vaccine that could save humanity, was being securely kept in a high-security facility. However, one day, it was suddenly stolen by an unknown assailant and vanished without a trace. Meanwhile, Emilia, alongside the electronic lifeform Brain, continues her daily pursuit and capture of fugitive bounty hunters. One day, a man known as Itachi, a notorious information broker, appears and reveals the news of Zaurum's stolen head. With the promise of a massive reward for whoever retrieves it, Emilia begins a new battle to reclaim the prize.