The two with the most interesting hair….
What evidence is there that it could work?
Duo never takes it personally when Trowa throws him in a cell ^_^
Trowa cried when he destroyed Duo's Gundam.
There is no obvious proof for this couple, other than the fact that they don't ever argue (not that they spend much time together, either). If they ever did end up together, Duo would at least be able to help Trowa rediscover his emotions, and would probably be glad to do it. Trowa is a fellow, and Duo wouldn't hesitated in trying to help him in any way. Similarly, Trowa sees Duo as a comrade, and therefore would do the same. Trowa definitely needs someone caring to help him out of his shell, and Duo needs someone that he can depend on while at the same time care for.
What evidence is there that it wouldn't work?
Trowa does have a habit of throwing Duo in cells….^_- (just kidding)
Trowa and Duo don't really spend any amount of time together during the show or Endless Waltz, so it's a little unclear as to how they would interact with each other in a more casual setting. Besides, Trowa is more concerned with Quatre and Duo with Heero/Hilde for them to notice the other.
In Conclusion
Trowa and Duo have something in common because both have grown up in group settings: Duo with his street kid gang, Trowa with the mercenaries. That in itself connects them, in that they both seem to feel more secure with allies. They work well together and they're friends. No need to get mushy. ^_^
