Kei and Yuri, initially junior agents at the Worlds Works and Welfare Agency, were paired as the "Lovely Angels" codename. Their partnership began with an initial reluctance, as they both had reasons to dislike each other, including Kei's previous disciplinary issues and Yuri's reputation for dating. Despite their rocky start, they continued to work together, earning their nicknames "the Dirty Pair" due to their unintentional collateral damage. This series is an alternate universe take on Dirty Pair, set in the years 2248-49.