There is a good argument that this is the most atmospheric shrine at the foot of Mount Fuji, and it has nothing to do with the view. Omuro Sengen-jinja stands in a grove of huge old cedars on the northern side, close to the lake town of Kawaguchiko, and the trees are so tall and so quiet that the sound of the road disappears within a few steps of the torii. The shrine is attached to the cult of Fuji itself, the idea that the mountain is a goddess to be placated, and it is part of the World Heritage listing for Fujisan as a sacred place and not simply a pretty one.
The history is volcanic. A great eruption on the mountain's flank in the ninth century sent lava into the area now known as Aokigahara and dammed lakes, and shrines like this one were built to calm the deity. Centuries later, the Fuji-ko brotherhoods of Edo pilgrims climbed the mountain in white robes and used cave sites in the lava fields as places of prayer and rest, which is what the neighbouring Hitoana label points to. Today the shrine is quiet, with a small wooden hall, mossy lanterns, and a path that leads to the edge of the forest.
For the rider, the area is a pleasure, if you time it right. The roads around Lake Kawaguchi have good surfaces, gentle climbs and long open bends with a clear view of the mountain, and the Fuji Subaru Line climbs toward the fifth station through forest and then bare cinders. It is a toll road and it is closed by snow for much of the winter, so check before you point a bike at it. Weekends in summer and on public holidays bring an immense amount of traffic, and the best hours are early in the morning, when mist hangs over the lake and the cone is sharp against a pale sky.
Fuel and food are straightforward. Fujikawaguchiko and Fujiyoshida are both real towns with stations, convenience stores and good bowls of houtou, the thick miso noodle stew that Yamanashi lives on. Bring a layer: at this altitude the temperature drops fast after sunset, even in July.