Dozens of hunters and police in the city of Utsunomiya, north of Tokyo, are searching for the animal after more than ten reports of bear sightings have been received since Saturday - including in a shopping street.
"We have vehicles out in the areas where a bear has been seen to inform people and urge them to stay indoors or in their vehicles," a city official told AFP.
A total of 94 municipal primary and secondary schools were closed.
The bear being hunted is described as being about one meter long, but it is unclear whether it is one bear or several.
Bear attacks in Japan have increased in recent years and have become a major problem. Last year, 13 people were killed by bears in Japan, a record.
