JapanesePod101, the very popular Japanese learning site, podcast, and chain-email provider, has begun broadcasting a twenty-four hour stream on YouTube. Even though the name says "Learn Japanese in 24 Hours," that's not the goal (we see what you did with that typo).
It's not actually "live" in the typical streaming sense—it's more like a TV station for people interested in learning about Japanese language and culture. Different pre-recorded, short programs explore tourist areas, cultural norms, food, and teach beginner vocabulary. They also have sections dedicated to learning new words. Some are spoken mostly in Japanese with English subtitles, so it isn't just for beginners, and there are tons of random things you can learn just by having it on in the background.
This stream won't teach you Japanese in 24 hours, but it is like an NHK channel with only one advertiser popping up each time you watch.