What's in a Name?

There is an attractive suburb in the western part of Tokyo named Hino City. Hino is written with the characters for "fire" and "field". How did it get this name?

One rather poetic explanation is that, because three rivers converge in Hino, sparks shoot off the water like sparks struck from a flint.

Another explanation is more prosaic. Since the most ancient days of human habitation (about 10 thousand years into the past) Hino has been a grassy plain. When grass gets dry, it burns.

Yet another explanation attributes the naming to the period of warring states in Japan when Hino, as the first high ground to the west in the flat area around Edo/Tokyo bay, was where military signal fires were set alight.

There is probably a little truth to all of them. Which one captures your fancy?