Most Jdramas are encoded using XviD, DivX, or h.264 and if you are having playback problems such as not seeing any video, chances are you are missing one of these codecs. There are a number of ways to resolve this problem.
1) You can download and manually install the missing codecs and play the video with your default media player.
2) If your computer is pretty old (circa 2000) you might want to consider using VLC media player because it already has most of the codecs you will ever need built-in and it uses little processing power which gives you a good chance at playing the video back at full speed. Another option that you can try is the Combined Community Codec Pack but CCCP needs a bit more speed than VLC.
3) My personal favorite option is to use Media Player Classic with fddshow tryouts. You might have to configure it a little but it has excellent playback quality without using unneccesary system resources like some other media players out there.
There are many versions of MPC available on the internet. Try them out and see which one you like the best.