Which county in Japan is Kawaguchi Lake?

Hekou Lake is located in Fuji Hekou Lake Town, Yamanashi Prefecture. It is one of Fuji Five Lakes;

Geographically, estuarine lake is also called "terminal lake" and "tail lake". Refers to lakes at the mouth, tail and tail of inland rivers. In addition, Hekou Lake, Benqi Lake, Jinjing Lake, West Lake and Yamanashi Lake in Japan are called Fuji Five Lakes and Yamanashi Prefecture at the northern foot of Mount Fuji. Hekou Lake is the second largest of the five Fuji lakes (the largest is Yamanaka Lake), with an altitude of 83 1 m, a maximum water depth of 15 m and an area of 5.7 square kilometers.