
The braided wonder and his perky side kick.
Duo allowed Hilde to work with him, and even lives with her for a long time on the colonies (ep ??)
Duo smiles fondly at Hilde when they’re working together on said colony (ep ??)
Duo is really worried when he hears about Hilde escaping from Libra.
Hilde abandons whatever life she had with OZ to follow Duo (ep ??)
Hilde infiltrates Libra in order to obtain information for Duo at the risk of her life (ep 4?)
After Endless Waltz, Duo and Hilde are still working together.
Duo and Hilde obviously work very well together as a team. Duo enjoys the company (as someone who’s used to having company) and Hilde is happy to help him in any way she can. To Duo, Hilde is another group member for him to attach to. More importantly, she can take care of herself in most situations, so he doesn’t have to worry about sheltering her from the war or his work (a civilian might not understand Duo’s justification of killing people for peace). She’s optimistic and caring, like him. To Hilde, Duo is just what she needed. The size of Duo’s fan list is proof enough that girls go crazy for the guy: he’s handsome, smart, funny, sticks to his ideals and fights for a better future. Hilde obviously thought she knew where her life was going, but Duo’s strong convictions changed her almost instantly. Duo is Hilde’s symbol of strength, in a very similar fashion to Heero and Relena.
Duo’s a very open person by nature, so it’s not surprising that he would allow Hilde to work with him in the absence of the other pilots. Which also means he’d have no problems continuing to work with her after the war—if anything, though could just be friends.
Hilde doesn’t seem to be the most stable person anyway—after all, she did abandon her entire career and risk her life for almost a total stranger. She’s a very surface person who believes heavily in conceptual reality; caught up in the beauty and honor of fighting for one’s home, she loses sight of the grim cruelty of battle. She tries to be like Duo, unknowing of how deeply the horrors and guilt of war are affecting him. Hilde sees the end of the war while Duo sees each battle. In effect, she’s somewhat two-dimensional—not to insult any Hilde fans. She’s certainly optimistic and caring, but it’s not likely that she’ll ever seriously consider the deaths she caused in working for OZ. She’s innocent and naïve.
Duo may seem to be very much the same, but there’s enough evidence to indicate that there’s a lot more going on inside his mind. At the end of the war Duo is going to have to look back, consider what he’s done for the sake of “peace,” and come to terms with it. For someone that loves life and people as much as Duo, overcoming guilt is going to be a big part of that (hope you read the Duo section). Though it can’t be assumed what kind of life Hilde has led up until entering OZ, she gives no indication of any hardships in her past—again, she’s innocent. As young as they both are, Hilde probably wouldn’t understand the kind of pain Duo has suffered in his life, nor the idea of seeking repentance for his sins during the war. She sees him as a hero, someone for her to look up to. If Duo were to have a problem adjusting to normal life after the war, most likely she wouldn’t know how to help him.
In Conclusion
There’s not enough evidence in the show to prove either one way or the other. But since they are together a year after the war, obviously they enjoy each other’s company, if nothing more. No other couple is pictured as having lived together that long, which places them ahead of, say, Zechs and Noin or even Heero and Relena. Both are quick to trust and are very protective of each other. All this points to the likely possibility that Duo and Hilde may link up in the future. However, in order for that to happen, Duo is going to have to overcome his own issues, and Hilde is going to have to accept that he is still a young boy, not invincible. If they can grow through these trials together, I see no reason why they wouldn’t work out, but it would take a lot of strength and understanding on both sides.