FYI - long-running, still active thread on this very subject at d-addicts:
http://www.d-addicts.com/forums/viewtopi...start=1125
(EDIT: Oops - Rich_F beat me to this months ago. Guess it would help to read what other people post...)
If you don't want to get a device or don't need to record, check out
http://jpplayer.com/. For a little more than JapanTV, you can get a full roster of Japanese TV channels on demand with high streaming quality. Seems like it's been around for years, and should it (*ahem*) disappear for some reason, your sunk cost will be low.
EDIT2: For a free alternative, this is apparently the new NIJI -
http://tvapp.so/. Not as many Japanese channels, but it has NHK, 日テレ, Fuji, TBS, and some others. Using it now, and it works very well - great video and sound quality.
I also found that iHome has a PC desktop version, and you can get a three-day free trial to check it out. This is really palatable to me, as I just popped good money on a new Intel NUC and would rather leverage that than buy a brand new device. I'll give it a test drive and report back.
Edited: 2015-08-15, 5:53 pm