The sun rises on Japan. More than 6,000 islands on the edge of the Pacific. Life here is at the mercy of Earth's most powerful elemental forces. From the wilds of the frozen north. To the subtropical warmth of the south. Animals along this chain of islands have had to adapt in unique and sometimes bizarre ways. Throughout this land, people have developed an extraordinary relationship with the natural world. Trying to capture its fleeting beauty. And tame its spirit. But these islands remain wild, mysterious and magical. This is Japan. Captions were made possible with funding from NZ On Air. Able 2017 There's a corner of Japan that's a world apart from the rest of the country. It's the northernmost frontier. This island endures a brutal winter that locks the land in snow and ice. The animals that live here would look more at home in Siberia. All life is ruled by the changing seasons. Summers are brief and autumns dazzle. This is a land of tough animals and hardy human souls. Sometimes you need to build unlikely alliances to survive on Hokkaido, Japan's wildest island. An Ussuri brown bear is patrolling the Shiretoko Peninsula, in the extreme northeast of Hokkaido. It's September. She's waiting for a bounty that comes this way every autumn. Tens of millions of Pacific salmon are gathering off the coast. Soon they'll swim inshore to spawn. And that'll bring them within snatching distance of the female bear. She needs to put food in the mouths of her two young cubs. There's a bitter winter coming, and if they're not well-fed, her cubs won't make it through. This is a hard place to be a mum. The family is not alone. This peninsula is home to 200 brown bears. It's one of the most densely-packed populations in the world. The salmon bonanza has attracted others here, too. Nobody lives permanently in this remote part of Hokkaido. But one hardy group have special permission to stay here for some of the year. Hokkaido is Japan's second-largest island, but the harsh conditions mean it's home to only 4% of its people. Shiretoko is one of the loneliest corners, where you have to live close to the wild. Brown bears can weigh 300 kilos, and are not to be messed with. When bears and humans cross paths, things can get dangerous. But here, something astonishing has happened. For the fishermen, bears have become a part of everyday life. It takes some nerve, but the men live alongside them as equals. Tough characters, side-by-side, both dependent on the salmon run. The mother bear knows what she's doing. Survival is in her blood. Her ancestors came to Hokkaido from Siberia. And they walked here. 12,000 years ago, Hokkaido was joined to the Russian mainland. Siberian animals colonised it, before the sea levels rose, turning Hokkaido into an island. It's why the wildlife here is so different from the rest of Japan, and so well equipped to face the coming winter. By the end of September, it's getting colder in the heart of Hokkaido. And the forests are starting to glow. The intense colours are created by the warm days and cold nights of Hokkaido's autumn. It's one of Japan's most beautiful natural displays, and the forest fills with visitors. Every autumn, more than a million Japanese tourists travel to Hokkaido. Vivid autumn leaves are called koyo. In Japan, people have been making special trips to see them for over 1,000 years. And, because it's so far north, Hokkaido is the first place where koyo appears, hustled in by the chill of an early autumn. It's a fleeting display. There's barely two weeks to catch the best koyo before it vanishes. And soon, the fair-weather tourists will disappear too. Every one of Hokkaido's inhabitants has to deal with the island's seasonal extremes. And that includes some extraordinary life-forms that live at the bottom of a lake. They may look like mossy boulders, but these strange balls in Lake Akan come to life when you speed up time. This spinning seems miraculous. After all, these aren't animals, but an incredibly rare form of algae found nowhere else in Japan. They're called marimo. Or, in the local language, "marsh monsters". They can live for decades, and grow bigger than a basketball. The marimos' dance is caused by Hokkaido's elemental forces. The mountains funnel winds towards the lake. The resulting waves spin the marimo, shaping them into spheres. But, if the waves are too strong, it can be disastrous. Washed ashore, larger marimo collapse under their own weight. Battered by waves, they disintegrate. But marimo bounce back. Next spring, these fragments will start growing into a host of new balls. . Snow on the hilltops is a warning that autumn is nearly over. It's October. To the east, on the remote Notsuke coastline, a battle's about to start. This alien landscape is stark, even for Hokkaido. Nobody lives here, but all summer long, trawlers have been busy catching prawns off the coast. Now, the fishermen are packing up and shipping out before winter arrives. But others are made of tougher stuff. Sika deer live here year-round. Right now, they're gearing up for the most important event in their calendar. This stag has built up a harem of females. He can't hang about. A harem in heat is a magnet for other males. The dominant stag has no choice but to go and meet his rival. It's the newcomer that's won. He has the pick of the females for now. But it won't be long before other stags move in to challenge him. Many males are so exhausted they just won't make it through the winter. But at least some will leave a legacy. The females are pregnant. They'll need all their resilience to survive the lean months of winter. 70km to the north, back on the Shiretoko Peninsula, the mother bear is trying to feed her cubs. Pretty soon, they'll have to go into hibernation. They'll be holed up together for five months without food, so it's vital they lay down fat reserves now. The salmon have arrived. By watching underwater, the mother bear tries to get a head-start in the chase. Now the mother bear's finally got her eye in, there's no stopping her. The cubs still have a few weeks left to bulk up before hibernating. I love watching rugby with you, but I can only imagine how good it would be at a decent volume. Right now healthy hearing is even more affordable, with... Offer ends 30th of April. TINKLY MUSIC Staying on top can take an extra boost. Sometimes you need an energy drink with something more - something smarter, healthier. Introducing new Berocca Forward. We've added vitamins, minerals and the natural energy of guarana. Now that's forward thinking. Berocca Forward - more than just energy. . In December, winter arrives in force. A colossal mass of freezing air barrels in from eastern Russia. Crossing the Sea of Japan, it picks up enormous amounts of moisture which it drops onto Hokkaido as snow. Over a metre of it can fall in a single day. The freeze intensifies in mid-winter. By February, sea ice closes like a fist around the coast. Nowhere else in the northern hemisphere does sea ice reach this far south. Steller's sea eagles. CHIRPING In winter, they fly in from Russia and join other birds eking out a living on Hokkaido's coastline. The sea eagles rule this roost. They're the heaviest eagles in the world. CHIRPING The birds are surrounded by the ghostly hulls of abandoned fishing boats. Winter has grounded the ocean-going fleet. But a little ice isn't enough to stop Hokkaido's fishermen. They venture out onto the surface of a frozen lagoon. And the eagles follow their every move. This band of brothers has been ice fishing for over 40 years. And for Mr Takahashi, the eagles are a lucky sign. The fishermen have built a relationship with these birds. It's a two-way thing. The nets are bulging and some of the catch is for sharing. As the brothers make their way across the ice, the Steller's sea eagles move in. SQUAWKING White-tailed eagles enter the fray. SQUAWKING On the ice, the boldest, brashest eagles do best. Huge flocks of black-eared kites join the party. They're only a tenth of the weight of the eagles. But what they lack in stature they make up for in bravery. In spring, the Steller's sea eagles will fly back to Russia, fuelled by the fishermen's generosity. Hokkaido's winter is a force to be reckoned with. 2,000 metres up, on the peaks that tower over the island, nothing moves. Even on the lower plains, the farmland is locked in thick snow. WIND ROARS This extreme season tests even Hokkaido's most adaptable inhabitants to the limit. CAWING But a remarkable group of people lived through thousands of winters here. Hokkaido was home to its own indigenous inhabitants... ..the Ainu. Their ancestors came from the mainland, just like the brown bears. These hunter-gatherers were well in tune with the natural world. They lived for millennia on Hokkaido before Japanese traders arrived, over 800 years ago. In time, the traders became conquerors. Since then, the Ainu way of life has almost disappeared. But the animals they worshipped still survive. CHIRPING The Ainu revered red-crowned cranes as gods of the marshlands. To modern Japanese, these birds are symbols of beauty and long life. SQUAWKING Hokkaido is the only place in Japan where red-crowned cranes still live. But settlers' farms have swallowed up the wetlands where they used to hunt for fish and insects. In these fields, pickings are slim. Last century, there were fewer than 30 cranes left in Japan. It looked like they might disappear altogether. CRANES CALL OUT But salvation has come from a small group of farmers. They don't just tolerate the cranes, they go out of their way to help them. Throughout the winter, they brave sub-zero temperatures to feed these giant birds. Over 100 hungry mouths gather every morning. Thanks to these hand-outs, the red-crowned crane has fought back against extinction. Hokkaido is now home to nearly 1,000 birds. CRANES CALL OUT Whenever cranes get together, no matter what time of year, they put on a show. CRANE CRIES It starts with a song. CRANES CRY OUT And then a dance. Cranes often pair for life, and this ballet is key to that bond. But perhaps there's more to it than that. It seems that dancing is something that cranes simply enjoy doing. Thanks to their own tenacity, and human help, these enormous, irrepressible birds have survived to dance another day. And on Hokkaido in deep winter, survival is the name of the game. . The Ainu people call the Shiretoko Peninsula "the end of the Earth". In winter, this northerly outpost becomes a snowy wonderland, and even more isolated. Brown bears are asleep beneath the drifts. But sika deer have nowhere to hide. Instead, they rely on their own extraordinary resilience. Pregnant bellies make for awkward snow ploughs, but the females take the drifts in their stride. Their favourite foods, bamboos and other grasses, are buried. But these are the toughest deer in the world. And they're prepared for everything winter can throw at them. Blizzards bury the deer's food deeper and deeper. So they look in high places. They'll even get by on tree bark. It's just enough to keep hunger at bay while they live off their fat reserves. But even in this bitter winter, there are a few places where Hokkaido offers some unexpected comfort. All across this icy island, there are hot spots. Hokkaido has 20 active volcanoes. And in places, hot gases escape from deep underground, melting holes in the snowy landscape. Hokkaido is alive and breathing. Lake Kussharo is all that remains of a colossal collapsed volcano, over 10km across. At the end of winter, the lake is a lifeline for migrating whooper swans. It's a warm oasis in the middle of a frozen desert. A thermal spring keeps this patch of water warm and ice-free. SWANS HONK Most swans only use the lake for a layover before continuing to warmer parts of Japan. But a few have learnt to save themselves a journey by spending the whole winter here. SWANS HONK This is the perfect place to strengthen old relationships, and make new ones. The swans will stay until the spring allows them to return to Russia to breed. They don't have long to wait. It's April, and there's another great seasonal change on the way. From winter to summer, the temperature can swing from 30 degrees below zero to 30 above. For Hokkaido's frozen inhabitants, the thaw can't come soon enough. The Shiretoko Peninsula is released from the grip of sea ice. By May, everybody on Hokkaido reaps their reward for seeing out the winter. The island bursts into life. Spring is short; there's no time to waste. Farmers race to make the most of the growing season. Over the last century, Japanese farmers have transformed Hokkaido. Half a million tonnes of wheat are harvested every year. The most fertile parts of the island look more like rural England than wild Japan. And all this greenery is irresistible. The sika deer have started creeping into the lush cultivated fields. It's a whole new world. . These fields are brimming with specially-sown grass, intended for cattle. But this herd always seems to be one step ahead, helping themselves to the best grass before it can even be cut. Every year, deer can munch their way through over �30 million worth of crops. But some farmers have developed a live-and-let-live attitude. The deer are reaping the benefits of Hokkaido's human landscape. In a place like this, it pays to be adaptable. In the warmth of early summer, the red-crowned cranes have moved into the farmland waterways. And they have a new family member. They traditionally nest in marshes, but most have been drained. So the cranes are raising their chick in an irrigation channel. All through the summer, the chick will be entirely dependent on its parents for food. The channel is teeming with insects, fish and frogs. But the parents can barely keep up with their gangly offspring's appetite. The family won't be able to move on until the chick can fly. In the meantime, they can't escape from surprise visitors. The sika deer have managed to wander right into the path of a pair of cranes with a week-old chick. CRANE CRIES OUT Mum and Dad work together, to shepherd the chick to safety. And then, a quick flash of the dagger-like beak to make sure the deer keep their distance. CRANE CACKLES The parents' diligence has paid off. Their priority now is to feed their chick while times are good. All Hokkaido's inhabitants must rush to make the most of the short summer. Once the island blooms, some of the busiest workers fly into action. BUZZING European honeybees. People brought them to Japan more than 100 years ago. They're much more docile than the native bees. Every summer, Mr Seo brings his hives to Hokkaido. Mr Seo and his travelling bees have found paradise here. In July, Hokkaido becomes positively Mediterranean. While the rest of Japan swelters in a sticky summer, Hokkaido enjoys warm days and cool nights. It's the perfect place to grow flowers. For a time, Hokkaido brims with tourists who've come to soak up the beauty of this man-made spectacle. Their love of nature has drawn them from across Japan and East Asia. But Hokkaido's summer is short. Soon, the blooms will fade and the tourists will go home. It takes a certain resilience to live here year-round. Mr Seo doesn't stay for long. By September, Hokkaido is already sliding into autumn. Leaves that only grew a few months ago are changing colour and dying off. Hokkaido never stands still; its seasons rush by. This hostile frontier has long been a place that tests life to the limit. But its extraordinary inhabitants are more than up to the challenge. And they've discovered that by forging new alliances, they can deal with everything that the toughest corner of Japan can throw at them. All across Japan, from the mountains of the heartland... to the southern seas,... people still celebrate its unusual nature and fleeting beauty. Japan may be one of the busiest places on Earth, but the connection with the wild still runs deep.