This series ended late last year. It consists of 12 ~50 minute episodes (1 hr airtime). It is sort of set in Feudal Japan, and has sword fights (sort of). Anyway, the animation, plot, pacing, and action are all very well executed in this series, so I recommend you watch it if you haven't. 7/10.
For those of you who have seen it:
The last episode blew my mind. I honestly did not see that coming at all. It made me sad, but at the same time I didn't think it was a bad ending.