This is a great trail. This trail was very difficult to find, but a fun beginner to low intermediate ride trail of about 8 kilometers of rich trail goodness. This trail is on the outer limits of the Minakami area, but not directly connected to the town and most of the folks working in town have no clue where this place is. You will need to gain assistance from a Japanese friend or co-worker to help you look for the specific directions as the trail touches down in both the Nagano and Gunma-ken prefectures.
The overall way to reach this location is by car taking the Kanetsu expressway from Tokyo towards Nagano, take exit 14 and make a right onto the main road. Follow the main road up the pass 30 ~ 40 minutes and you will recognize the trail on the right hand side along the pass as there are several area to park. My recommendation is to go all of the way up the pass through a 4 kilometer tunnel and then park at the open parking lot.
Accessing the trail is very easy with minimal climbing of just about 5 minutes and a great ride after that; however the return up the pass will be about 9 kilometers of climbing on pavement where you get to break a good sweat unless you go on a rainy day as I did to keep cool.