
First, there is a long snout with two black nostrils as full stops. The mouth is open, as if in shock. Eyes that could be made of glass in a huge, wide head beneath cartoonish round ears. He waits. The metal shutter is lifted. The eyes peer, anxious. And then a huge paw, nails so long they remind me of Freddy Krueger, takes a very first step on to grass.

Kai, a 17-year-old Ussuri brown bear who has lived in a 6ft by 9ft cage since being snatched as a cub from his mother – who was shot by hunters – places a paw on something that isn’t cold, hard concrete. Yikes!

He snorts. He can’t believe it’s soft. He spies a toy, donated by the local fire service, one of many made from old hoses.

Kai has never owned a toy. He picks it up and, thrilled, carries it inside his den.

The keepers at Yorkshire Wildlife Park near Doncaster don’t want to cheer, as that would be alarming. Instead, water leaks from eyes as phones are held aloft to record this momentous moment.

Kai's first glimpse of the great outdoors: Wary Kai inches towards the open gate of his cage, watched by a warden. The 17-year-old Ussuri brown bear has lived in a 6ft by 9ft cage since being snatched as a cub

A nervous look around: Not sure, but with one paw out, he looks as if to say: Where am I? He stepped out of his cage for the first time after being taken from Japan to Yorkshire Wildlife Park

Kai is one of four bears who existed as ‘living’ exhibits in the Ainu Culture Museum on Hokkaido, the northernmost of Japan’s islands. The cubs were once sacrificed, but when that practice ended they were simply locked up. These brown bears are rare: there are only about 10,000 left in Japan.

Eighteen months ago, Western tourists, shocked at the barren conditions, brought the four bears to the attention of Wild Welfare, a UK charity that helps captive wild animals. The two brothers, Kai and Riku, would eat, then vomit, as that gave them something to do; all four bears would pace, driven mad with boredom.

‘The museum wanted the bears rehomed,’ Georgina Groves of Wild Welfare tells me. ‘They didn’t have the facilities. Unfortunately, we couldn’t find anywhere in Japan that would take them.’

She got in touch with Yorkshire Wildlife Park (YWP), which has an incredible reputation for rehabilitating wild animals. They said yes, of course.

Kai and his fellow inmates were flown 5,400 miles from Japan to the UK, where they arrived on August 3. DHL provided air-conditioned road transport – at a discount price – while the bears were flown in the hold by Japanese Airlines. The journey alone cost £150,000.

A team of five vets – two from Japan – helped with the move, which began in 36C heat. Only Hanako, the 27-year-old female, the most inquisitive of the four, went willingly into a crate. Amu, 27, a gentle giant, and brothers Kai and Riku had to be tranquillised.

First step to a new life: Kai tests the ground with his claws, literally, as he is tempted to explore further. Eighteen months ago, Western tourists, shocked at the barren conditions, brought the four bears to the attention of Wild Welfare, a UK charity that helps captive wild animals

Now Kai gets stuck in: Clear of his cage at last, he soon finds a fresh, tasty morsel to munch on. Kai and his fellow inmates were flown 5,400 miles from Japan to the UK, where they arrived on August 3

The bears were flown first to Tokyo for the connecting flight to Heathrow.

Alan Tevendale, one of the vets, says: ‘We offered them water when we landed and fans were placed around the cages. Conditions were not ideal. We were anxious.’

When the bears arrived in Yorkshire, tired and confused, they were given time to emerge from the crates, and venture into their huge, enriched dens: deep straw beds, water, and fruit, vegetables, yogurt and eggs.

They were also offered strawberries and, you guessed it, honey. As greedy as Pooh, the new diet ‘never touched the sides’ says Debbie Porter, animal manager at YWP, one of a team of five devoted to their care.

It’s all a far cry from their diet in Japan, where they lived on scraps. ‘We have many, many tins of pilchards,’ adds Debbie.

Hanako and Amu are hidden away in two dens out of bounds to anyone other than their carers: they will take a few weeks to recover from their journey, not to mention their 27-year confinement in a cage where they were only able to take four steps. But today is the first time the two brothers (‘They do look very alike,’ says Debbie) have been offered the freedom of the four-acre, £400,000 compound, enriched, thanks to volunteers, with climbing frames, a hammock, a giant tyre and a wobble pole.

Kai’s door is opened first, and he takes that all-important first step. After a sojourn back indoors with his fireman’s toy, he ventures out again, this time much bolder. Riku, the shyer of the two, refuses to leave his den, standing on his back paws unable to believe his beady eyes. But there is no stopping Kai! He’s cantering!

Within minutes, having ripped the bark off a tree stump as easily as if it were a plaster, he has discovered the lake. Whoosh!

Having fun: Logging in to his new surroundings. When the bears arrived in Yorkshire, tired and confused, they were given time to emerge from the crates, and venture into their huge, enriched dens: deep straw beds, water, and fruit, vegetables, yogurt and eggs

Making a splash: Within minutes, having ripped the bark off a tree stump as easily as if it were a plaster, he has discovered the lake. Whoosh!

I call Georgina to tell her we’re filming Kai swimming. ‘This is a bear,’ Georgina says, her voice thick with emotion, ‘who only had three inches of water in his cage for 17 years.’

Kai splashes. He dives. He pulls up the lovingly planted aquatic plants, and eats them. He emerges, all half a ton of him, and shakes the water from his fur.

The bears know their names but, though being called, Kai is pretending he has gone deaf. He’s refusing to come in. For the first time in his life, he is being a bear.

The bears have no muscle definition, rotten teeth, and weirdly no eyebrows: the hair has been eroded by the constant rubbing on the bars of cages. There are bald patches on bottoms, and their coats are dusty.

Apart from the fur on Kai, of course, now sleek as an otter, and who is still refusing to come in. ‘They are like naughty toddlers,’ says Cheryl Williams, one of the directors at YWP.

The rescue effort is commendable, bringing the plight of captive Japanese bears to worldwide attention – the bears were even an item on the Today programme.

Georgina says: ‘We can’t rescue the 400 bears left behind. But we can educate people in Japan about enriching their environments.’

For now, Hanako has stopped pacing, while the brothers have stopped vomiting. Over the next few weeks, they will be allowed outside in pairs. It’s hard to comprehend that, since cubs, they have only been able to touch nostrils through bars. It’s hoped they will rough and tumble, collapse in a fireman’s hammock, and perhaps even give each other a bear hug. I’m betting Kai will take Riku by his paw, and lead him gently to the lake to wash away the past.

As we tuck the bears in for the night, I’m allowed to feed Riku a pear. He’s surprisingly dextrous, and I’m told not to get too close.

But who could blame him if he were to rip a human’s head off. We surely deserve it.

To support the work of Yorkshire Wildlife Park’s charity click here.

You can find more details about the bears by clicking here.

Leaving all this behind: the bear's old home - a rusty 6ft x 9ft cage in a Japanese museum