I did in 2005/6. It was a fantastic experience. But it was also a challenging year. I was in a small town. I didn't speak Japanese at all. I found just going to the supermarket stressful. The people in my town didn't speak much English at all.
The school underemployed me and there was a period of about 2 months when I didn't have one class. I couldn't drive which was annoying but the trains are very very reliable and I bought a push bike which everyone has and you can cycle on the pavement.
Plus sides - looks good on a cv. Travelled to Thailand , china and Malaysia and other bits of Japan.
Honestly, I broke up with a guy I was in love with to go so I think because of that I struggled to settle in . If I hadn't had that issue then I think it would have been amazing.
It is such a culture shock though and I say that as someone who has lived in other countries.
There was a while staff room meeting which lasted 30 minutes and when I asked what it was about, it was because one of the students had been hoarding text books. I couldn't believe how generally inefficient they were. I couldn't to begin with believe how they never questioned authority. It was literally freezing and the heating wasn't on. I was sat with scarf and hat at my desk but no one was willing to ask for the heating to be put on. It was then that I could see how they ended up in world war 2 the way they did. I apologise if anyone finds offence with my observations.
Looking back it was amazing . It was quite hard at the time. But it was worth it.