Double or Nothing does a great job of capturing the vibe of Dirty Pair while taking that concept and showing how it can be expanded into other genres. It distills it down to the "buddy cop" action story combined with a romantic comedy/sitcom romp and finds ways to emulate both of those styles through quick, easy to grasp, and downright DIRTY mechanics.
First off is the way it plays out the friendly "competitions" these sorts of pairings naturally get into. You literally keep track of who is scoring more "points" with the characters' current crush or who's clobbered the most bad guys. It codifies the sort of thing players would normally do if they get into this sort of scenario.
The same goes for the flirting mechanic. It depends on the sorts of peeps you play with, but this sort of interaction comes about naturally in the groups I've gamed with over the years, so seeing something that gives a mechanical bonus to a thing that already exists is pretty cool. It shows that the people who made this game get the way certain groups interact and find ways to work that into their design.
Keeping tabs of the collateral damage caused by both sides of the conflict, and judging "success" on whether the players can cause less damage than the bad guys is a pretty clever take too. Going by this I'm sure the Dirty Pair themselves rarely actually WON an episode, and I'm sure plenty of PCs will be recreating that outcome.
Haven't had a chance to actually play this yet, but reading it over tells me it's definitely gonna be something that'll click with my gaming peeps if I ever have the chance to run something with just two other players. Rad stuff.