Shin Sakamoto, who heads the volunteer diver group, calls for a stop to coin offerings into Wakuike pond, created by the Oshino Hakkai spring waters, in Oshino, Yamanashi Prefecture, while group members pick up coins from the bottom of the pond on July 22. (Video taken by Takuya Isayama and Kotaro Ebara)

OSHINO, Yamanashi Prefecture--If local government officials and a volunteer divers group have their prayers answered, visitors would stop tossing coins into a pristine pond here as a "saisen" money offering.

Volunteers dived into the cold waters of the Wakuike pond from the early morning of July 22 to retrieve coins scattered along the bottom. The crystal-clear water is a bitingly cold 13 degrees throughout the year.

A few divers worked for around 20 minutes, each in turn.

“Even though we pick up coins from the pond, the situation returns back to the same in about three months," said Shin Sakamoto, 51, who heads the volunteer diver group. “It would be ideal if divers do not need to enter the water.”

The Oshino municipal government has long been calling for a halt to the offering of coins into one of the eight Oshino Hakkai ponds formed by snowmelt from Mount Fuji.

The practice is deteriorating the quality of the water as well as spoiling the view of the bottom of the pond for visitors.

Oshino Hakkai is one of the 100 springs and rivers recognized by the Environment Ministry for its clean water, and is a popular sightseeing spot.

Mount Fuji, along with its surrounding areas, was designated by UNESCO as a World Cultural Heritage site in 2013.

After that, the number of visitors including foreigners has increased. Subsequently, the number of coins thrown into the pond also increased, as it is believed to have become a makeshift saisen box.