I first saw this film over a decade ago and loved it. I re-watch every few years or so. Yes it has flaws, but the relationship between the leads is warm and touching. I watched it for them and still love it to this day because they also are among the most talented Korean stars and made me love their characters. The film introduced me to Korean movies 13 years ago, and I've loved them since.
For me the beauty of the film, based on history but with a romantic overlay, is its story of the young queen's devotion to duty, as well as the swordsman's devotion to honor-and protecting her. He will not leave her side, and she is equally brave and stalwart. It is the story of a woman's love of country and a swordsman's love of her. And it's achingly beautiful.