Hiking through the hills of a national park in Japan's northernmost main island of Hokkaido has become popular for the opportunity it presents to see wild brown bears in their natural environment.

The hiking route in the Daisetsuzan National Park is open only from late June to early October -- and closed when the park's brown bear information center judges conditions too dangerous.

Hikers are allowed to walk the trail without a guide after hearing a lecture about brown bears, including prohibited behaviors such as cooking in the forest, locations where visitors should not eat, and never to leave waste behind.

The 7-kilometer route that takes visitors to ponds in the mountainous area in Kamikawa boasts a high chance of seeing bears in the distance. Since the opening of a supervisory office in 1994, no trouble between human beings and bears has occurred.

"If we keep an adequate distance, we can coexist with them," the center says.

The number of foreign tourists has increased in recent years after the route, called Daisetsu Kougen Onsenn Spa Numameguri, was introduced by a Lonely Planet travel guidebook.

On one early morning in August, a couple from Germany were excited to see one adult brown bear with a cub eating grass about 200 meters away. Using telescopes, the couple observed the bears which appear to be around 1 to 1.5 meters tall.

"Many of the bears here are gentle in nature and run away soon when being approached," said Hitoshi Yanagisawa, 43, a brown bear information center official.

The area is a popular feeding spot for brown bears because of its moistness and rich vegetation, and around 30 bears are seen there every summer.

Visitors can walk the route from 7 a.m. to 3 p.m. during the open period. Information center officials patrol the route every day and post information on a notice board in the center about where bears were recently spotted or their footprints found.

According to the Hokkaido prefectural government, 14 incidents involving brown bears were reported throughout the prefecture over the five years through March 2016. In some cases, people were attacked by bears when they entered a forest to collect edible wild plants.

The center plans to analyze its accumulated data on the biology of wild bears and launch an eco tour for visitors seeking to see the animals in the wild.

"I had been thinking bears are scary, but they were so cute when I saw them from a distance. My image of bears has changed," said one visitor.

Yanagisawa said, "Bears are smart, and they may understand when and where humans are present and thus do not come forward."

"We can sneak a look at bears' natural behaviors, like sliding down snow-covered hills and swimming in ponds," he smiled.

Brown bears are distributed across much of Eurasia and the northern parts of North America. In Japan, they only inhabit Hokkaido, while smaller Asian black bears live in other parts of Japan. Adult brown bears can grow to more than 2 meters tall and weigh 300 kilograms, making the species the largest terrestrial animal living in Japan.

The bears are omnivorous -- eating grass, nuts, salmon and deer -- and remain dormant during the winter.

Sometimes brown bears wander into areas inhabited by human beings, ruining farm crops, killing domestic animals and even attacking people they encounter.

The number of brown bears in Japan is estimated to be increasing, partly due to a decline in the number of hunters.

"We want people not to just be afraid of them, but to come to see them living in nature after fully understanding that this is a place where bears live with a sense of awe toward them," said the center's chief Yasuhiro Sato, 75.