Asteroid 3751, Zao, was discovered on January 5, 1992 by Masahiro Koishikawa at Ayashi Station, Sendai Observatory near Sendai, Miyagi,Japan. It has a period of 3 years, 18 days and is slightly less than a mile and a half (2.3 kilometers) in diameter.
It was named for Mount Zao, a mountain on the border between Yamagata and Miyagi prefectures in northern Honshu. It is a complex volcano (consisting of a cluster of volcanoes) and includes a crater lake, Okama Lake, which is known as The Five-Color Lake because it changes colors with the weather. Mount Zao is also known for its ski resorts and the "snow monsters" created by wind blowing water droplets off the lake against the trees and snow falling upon the resulting icicle formations.
The astrological meaning of Zao seems to be: a huge obstacle, heroic battle.