Synopsis: Kenshin Himura is a young man who had been orphaned early in life. Raised and trained by a Mitsurugi sword-style master, Kenshin decides to take leave and fight for a new world when he reaches his teens. Soon, Kenshin becomes one of the most feared assassins of the Tokugawa era -- for beneath the boyish frame and face lies a merciless killer of unparalleled skill. But something changes within Kenshin the day he meets Tomoe, a beautiful young woman who seems to have dark secrets of her own.
Review: Whether you've watched the Rurouni Kenshin TV series or not doesn't really matter. Rurouni Kenshin the OAV series is awesome to say the least, and you can enjoy it without any Rurouni Kenshin background.
The tone is solemn, and there is never a comical moment. This seriousness is reflected from the color schemes and composition of the scenes to the way the characters speak. Even the music reinforces this mood. The fights are virtual bloodbaths. People are slashed left, right, and center. You'll definitely be seeing a lot of samurai action and a whole lot of red. For those who've watched the TV series or read the manga, you'll find that the Kenshin here never lectures his foes to submission. He just kills, kills, kills... and you'll come to understand how he gained the title of "Battousai". You'll also discover how he got that X scar on his cheek.
Characterization is excellent, as is always the case with Rurouni Kenshin. A lot of insight and depth is provided as to why these people are the way they are. You would really feel as if you knew them personally, which makes it easy to empathize with whatever it is that's happening onscreen. The cinematography is superb. The scenes were obviously composed with a lot of thought as to convey additional meanings and emotions in every frame.
The art and animation are very good, and a lot different from the TV art. The way the faces are drawn in particular reminded me of the style employed in "Serial Experiments Lain". The English dubbing is fine; I just can't stand their mispronunciation of "Tomoe". The original Japanese version features seiyuu Junko Iwao (also Mima in "Perfect Blue", Ceres in "Ayashi no Ceres"). Rurouni Kenshin the OAV series is easily one of the best OAVs out there, and that's coming from one whose fave genre isn't even action.
Miscellanies: I don't know why they chose "Samurai X" as the official English title of the OAV series. You'll get a lot more out of Rurouni Kenshin if you also experience the TV series. The Samurai X: OVA Collection bundles this together with the final OVA, Reflection.