Gunma’s “Niagara Falls of Japan” is a beautiful falls that is relatively unknown outside Gunma. It is in Numata, a small city well known for its beautiful nature and outdoor activities. The falls are only 7 meters high, but span a good 30 meters in length. Moreover, you’re able to go right up to the falls, which is a fun experience! There are also bridges above and below the falls, giving you a great chance for some nice pictures.
I visited the falls in winter, when the water level was at its lowest, and the vegetation around not very pretty. During summer the area around the falls are lush and green, but probably the most spectacular season is fall, when the leaves around the falls turn beautiful colors.
The falls aren’t easy to get to… the best explanation I found is here, and there are some really great pictures of the falls as well.