I've come to notice that there are few female characters in anime with seductive personalities.
There are characters who are physically good-looking, characters who are proud of their appearance, characters who are in love, and characters who try to get closer to the person they're interested in. Rarer is the type of female character whose mannerisms ooze fiery passion in such a way that their sexuality is more than simply their physical design.
Here's a character who I think qualifies: Fuwa Aika from Blast of Tempest.Good-looking but not to an incredible degree, you can sense in her interactions with her boyfriend Yoshino not only the way she focuses all of her charm on him, but also the strong physical and emotional response that Yoshino has to Aika's desire. It's difficult to capture this impression in a single image.
Another lesser example comes from a few years ago in Macross Frontier. The character of Sheryl Nome is more sexy than seductive normally, but in one scene both she and Ranka Lee are trying to out-sing each other in order to demonstrate their interest in the protagonist Alto and why he should choose one over the other. In that moment, both Sheryl and Ranka exude strong desires which fill the space they're in.
In thinking about this, I'm reminded of an old post on Heisei Democracy, in which Shingo states that . The argument is that lipstick denotes an assertive un-moe character, while lips in general are a sign of active sexuality which is counter to moe's ostensible image of innocence. I don't quite agree with that premise, and my discussion of characters isn't limited to just those who would be considered "moe," but I do feel like there's something relevant in Shingo's argument. There's this rough idea that moe characters, even when they are attractive or overtly sexualized, at most tend towards conflicted expressions of desire (e.g. tsundere) or displays of innocence even in less "innocent" moments. If you then move the idea to being about the difference between sexual/seductive, maybe it's not so unusual for seductive characters to be a rarity.