Gundam Seed: Lacus Cline
One of the characters from Gundam Seed is one called Lacus Cline, who's first introduced early on as a pop star singer on the Plants side when she's captured by the Alliance side. Before I watched the series, I could already tell she was a massively popular figure out of the show. Having watched it, I can understand why. This is because, at the beginning, you see her as a fluffy, feminine character who is nice, obviously naive and therefore harmless, with an unexplained but slightly annoying habit of getting out of any security enclosure she's put into. But, as the series progresses, she strikes out against the current Plant leadership by advocating a position of peace using her celebrity status to promote it. She helps one of the characters steal a top secret military weapon, disappears before she can get arrested and then turns up later to steal a top secret military ship, called the Eternal, leading a group of dissident military personnel in what was obviously a carefully planned and executed manoeuvre that had to have been going on behind the scenes for a large part of the series. She then commands the Eternal in battle against both the Earth Forces nuclear bombers and the ZAFT (Plant military) gamma ray laser. Although she retains her generally fluffy and feminine persona and never gives one single order phrased in the imperative in the entire battle, she nonetheless comes across as seriously implacable person who you do not want to mess with with a scary grasp of space combat tactics. The scene etched in my mind is when she's on the bridge of the Eternal and something (a missile or debris) slams into another part of the Eternal and she just spares a look of fleeting annoyance as it hits, which is the first direct time that you see the iron core at the heart of her fluffy personality. She is one of the first female characters I've seen where they managed to make the character both fluffy and feminine and pragmatic and capable, in a consistent and believable way. As a result, I can see why she's considered one of the most awesome anime heroines of all time, and I like her a lot too.