This is a little shrine at the peak of a mountain road, in between of multiple mountains, with a decent view.
The Kosei Shrine is at the end of an moderate accent, which you can do by road bicycle, but because of the forest works along the way and therefore rough road surface, I'd suggest you to bring a gravel bike.
Since it's easy to reach from the Chichibu city, you can plan visiting this shrine, preferably accent from the east and decent to the north, for a nice little loop.