Numerous Steller sea lions swim gracefully as if bouncing about with divers under the waters off Otaru, Hokkaido. (Video taken by Gen Hashimoto and Kotaro Ebara)

OTARU, Hokkaido--Divers frolicked with a herd of friendly Steller sea lions that arrived for the winter season in the sea offshore here.

About 20 of the 3-meter-long mammals slowly surrounded the divers about 10 meters below the surface of the sea, where the water temperature is about 8 degrees, compared to minus 3 degrees above the surface.

The sea lions were so curious that they sometimes moved their faces close to the divers to check them out.

The herd had set off from the sea around Russia, their breeding site, and are migrating to the waters around Hokkaido in wintertime.

“I did not expect to see that many Steller sea lions,” Saya Sasaki, 26, a nurse who came from Sapporo, said excitedly about the encounter, which occurred in late January.

Steller sea lions can usually be seen in the sea near Otaru from December through the early spring, according to Takashi Koga, 49, an Otaru Aquarium curator.