An appealingly playful polar bear has become a major attraction at a zoo in Kushiro, Hokkaido, where onlookers delight in seeing the animal rear up on her hind legs.

The 2-year-old bear, named Milk, was born at Oga Aquarium Gao in Oga, Akita Prefecture. She was transferred to Kushiro City Zoo in January last year and immediately gained fans: her antics were televised and shown online.

Milk is around 180 cm tall and weighs about 200 kg. She swims in her pool like a sea otter, throws a plastic container in the air and stands with a gas pipe on her head. Visitors are particularly impressed when Milk walks on her hind legs, sometimes taking nearly 20 steps.

"Milk appears triumphant and looks like she's gauging the audience reaction," said Hiroyuki Kubono, a 60-year-old handler. "I've never seen such a bear."

One onlooker, Misae Murata, 41, a company employee from Kushiro, said she visits the zoo to see Milk two to three times a month. "She is growing rapidly and developing her play, and I just don't want to close my eyes," she said.

Miyuki Takahashi, 34, who took care of Milk at the aquarium in Oga, said: "I'm happy to hear that she is loved by lots of people (in Hokkaido), just as she was in Akita."

Kushiro zoo believes the animal deserves an even wider audience. "We would like more people to come and see our idol," said a public relations official.