Immersion tools can be difficult to find, especially when it comes to anything besides text. When you're talking audio or video, it can also become very costly as well. However, my goal here is to provide as much material as I can find that's free, to open it up for more people to learn.
With that being said, I'd like to introduce tunein, a free website featuring free radio streams from all over the world.They have countless stations from all over the place. Most importantly, they have many, many Japanese radio stations.
One thing I should mention, however, is the fact that not all of them work 100% of the time. Some are links to sites where you must register, and some are down. If you trip over one of these, just move on to another one. I've found most of them to be pretty reliable. One I'm listening to now is "84.4 FMたちかわ" out of 立川 (たちかわ/Tachikawa) - it's talk radio.
Check it out and enjoy! Feel free to leave comments below if you find a station you enjoy!