Genmaru
Um, they are actually meant to be together. They bicker like Shikamaru's parents do. Shikamaru is a bit sexist, and requires a tough girl like Temari to keep him in line, like his dad.
They do bicker, but Shikamaru is actually quite different from his dad. Shikamaru's dad is actually pretty perverted. He loves women. Shikamaru is the opposite. He's scared of women. It has nothing to do with his age; he's 15 and still can't stand girls.
Shikaku is not quite sexist. Shikamaru takes his dad's example, and exagirrates it, like most kids do. Shikaku believes in the, "old-fashioned wife" concept but he DID marry a girl who was on the CONTRARY of those beliefs. I will say this as appropriately as I can; Shikaku likes to be dominated by a stronger-willed partner. It is clear that Shikamaru is quite indifferent, but hates girls who force themselves to the top (quite the opposite of his dad's opinion). Sakura and Ino are big-mouthed morons who make themselves noticed. If Shikamaru doesn't want that, he's in for some trouble because Temari is like that as well. A sister to Gaara, Temari finds a need to overcompensate; exactly what Shikamaru wants to stay away from. According to Shikamaru's preferances, there really aren't any girls around he would actually WANT. This assuming that Temari remains the person she has always been.
See, their friendship is like those between co-workers. You only see your co-worker at work, so you see their strong, bold work ethic. However, you don't see their attitude at home, school, or in public much. Shikamaru has ONLY worked with Temari, or fought her that one time. As for the other girls, he has seen them make complete asses of themselves, but since Temari is from SAND, he hardly sees her issues. Therefore, he has a pretty clouded vision of her as it is.
I'd love to say Shikamaru has a soulmate, but he doesn't. neutral