This is basically a game I thought of, basically you match characters in alien nine to characters in other series as there counterparts, but you must give reasons why you believe they are counterpart's, it's just supposed to be something fun to pass the time, I'll start one to show you how it works, also if you disagree with a counterpart idea you can say why you think they aren’t counterparts and who you think is the proper counterpart.
Alien Nine-Digimon Tamers counterparts(since I'm writing a crossover between them so I figured it was a good place to start).
Yuri-Takato-Both are the main character in there series, both are the last member to join there respective trio's, both can be fearful at times(yuri more then Takato), Both made a mistake which effected there partners(Who's was worse is debatable, Yuri's borg died temporarily, Guilmon turned into a monster).
Kumi-Rika-Both try to take leadership roles often, both start out disliking the main character in etch of there series but later become close friends with them, both are the most easily angered in there respective trio's(though Rika is a lot easier to anger then Kumi), both have no father present(Though Kumi's father is dead, we don't know where Rika's is).
Kasumi-Jeri-Both are rather cheerful individuals(at first), both have a characteristic that others view as strange or are startled by(Nya! Ruff!), Both have traumatizing experiences involving being absorbed(or eaten) by giant inhuman entities, both are somewhat traumatized by the loss of a loved one(though Jeri's mother died, Kasumi's brother just left), both are good friends with the main character of there series(though Jeri is probably closer to Takato then Kasumi is to Yuri).
I only did Yuri, Kumi, and Kasumi here because it's just a start up, but feel free to counterpart match as many characters as you wish...also somebody else please do this, it's no fun if I'm the only one.