Mughi is their pet cat, although he's a bit big for a cat. As Kei says, Mughi takes up the elevator by himself. That's probably because he's genetically engineered, but we don't know exactly what he was engineered for. Nanmo is their robot, who's really quite good. He's responsible for saving their lives even, more than a few times.
In a world 20 years after space travel was discovered, humans have super-cities manages by computers. Eleanor City, one of these cities, is run by a computer called Brian. Super computer Brian malfunctions and they have to save the city. Even computers have a reason for their craziness. The girls are going to have to figure out how to placate a computer who is feeling betrayed. Given that they're the Dirty Pair though, you can bet that they'll cause more destruction than you would ever think possible. After that, they're hired to take a trip on a new space ship cruise liner that the owners are worried someone is trying to sabotage. Once again, they'll do the maximum amount of damage possible to complete the mission. Not on purpose of course, but it's just their way. Next, they have to go to Planet Vega. Kei is upset because they have to cancel their vacation, but I like it because they get to dress up instead of their normal fighting clothes. Kei is in the super sexy, slinky clothes and Yuri wears a very feminine pink almost ballgown. Of course, these clothes are going to be a bit more difficult to fight in!
I'd bet you're starting to sense a trend here. Kei and Yuri show up and things explode. They even blow up an entire planet; a planet that they were supposed to save. Every now and then, they pull off the mission without destroying anything they're not supposed to. They still get in their destruction, but blowing up pirates is quite allowable destruction! When Kei has a date, things really get out of control given how determined she is to get there on time. Even when they're not on a mission, the Dirty Pair can cause a lot of destruction.
For the most part, the Dirty Pair isn't a very serious anime. They're two girls who are far from grown up and obsessed with boys. Still, they have some serious topics. It was a bit shocking see a transgender in an anime from 1985. Given the time, that was a very progressive idea.
The only special features available are trailers and a different show opening. You might also notice that the episode titles on the boxes don't exactly match the title that shows at the end of the credits for some reason, but they are close. The only real complaint that I have is that there is no English language track available. Granted I almost always watch anime in the original Japanese, but it's nice to have the dubs available just in case you're trying to do something else and just want to listen.
I've loved the Dirty Pair since I first saw it about 10 years ago. It's hand-drawn animation that you just don't see much of anymore. The plots are interesting, but not too serious. You can really watch the episodes in pretty much any order you want. If you're looking for a fun anime that will keep you entertained, go pick up the Dirty Pair today!