The source of Tengunoyu.
A close up of the source showing Ofudosamma.

The waterfall at the source of Tengunoyu.

O-fudo-samma (a God of Fire)

Close-up of Ofudo-samma

This statue was put up when the area was a center for mountain worship.
When the Kurobane-han took over the area and put an end to the Yamabushi
and mountain worship the statue wasn't touched.

At the beginning of the Meiji there was an anti-Buddhist movement
that destroyed many temples and statues,
but this statue, possibly because it's small, was overlooked and so survived.

When Kumagai Genzo took over Kita onsen
he found the statue and the source of Fudonoyu,
building his first bath-house at the Fudonoyu pool.