Korea, the late era of Joseon dynasty: Gyu-yeob (Jae-hyeon Jo) is a brutal but skilled warrior who starts tracing a mysterious assassin who has been murdering the King's ministers. Soon clues point to the assassin being Gyu-yeob's old military friend Ji-hwan (Min-su Choi) who he has fond but tragic memories of. What is the truth behind the revolutionary killer and his female assistant Shi-yeong (Bo-kyeong Kim)?
As can be expected from a historical epic, the sets, costumes and massive group scenes look authentic and the colours of the cinematography, such as the green forests and blue night scenes are a joy to the eye. Still, it's harder to sink into the world of the film than in, say, Yimou Zhang's masterpiece Hero, largely because of the restless camera-work that would be better suited in an urban modern-day action thriller than a historical warrior epic. The camera spins around the characters, constantly tracks them, shakes as if in the hands of an epileptic and even goes to very blurry slow motion for long periods of time, making the already hectic fight scenes confusing to follow. The calmer, more static shots in the peaceful scenes look very nice though; I wish this approach would have been used more prominently.
Technical direction issues aside, the film's writing isn't really among my favourites of the genre either. As Gyu-yeob is such a cold and aloof warrior, it is difficult to relate to him and his emotions about his long-forgotten friendship with Ji-hwan. Now the lengthy flashback scene detailing their time together interrupts the main plot for too long; perhaps a traditional chronological structure or showing smaller flashbacks more evenly would have worked better. The long-haired Ji-hwan is a stylish character though and easily carries the scenes where he is in. The female Shi-yeong receives less attention and her role doesn't come across a very significant one, despite her implied importance to Ji-hwan.
In summary, I think Sword in the Moon is a visually good-looking, but not very effectively directed epic in which the nature of friendship is a major theme. A calmer style of presenting the action scenes would have benefited the whole significantly and suited the extravagant, even pompous, music better. I guess the characters could also have been fleshed out better, but in spite of my complaints, the film is not terrible and fans of historical sword epics should find it easily watchable – give it a chance if this type of cinema is your thing.