Actor and idol Tomohisa Yamashita on nerves, intimacy and the reality of recreating the Antarctic in intense summer heat

As the sun goes down and interminable night engulfs the South Pole, the summer team of scientists at the Polaris VI Antarctic Research Station hand the keys to the skeleton winter crew of 10, who have signed up to keep the facility operational for the next six months. Three weeks before the “winterers” are due to be relieved, however, all contact with the installation ceases.

When the summer scientists finally return, evidence of ghastly goings-on emerges: the station is in darkness, blood stains the corridor walls, almost all of the winter team is missing … and soon the bodies begin to pile high.

Eventually, traumatised doctor Maggie Mitchell (Katharine O’Donnelly) is discovered in hiding and appears to be the sole survivor of some unspeakable calamity, but is she really alone, and is she victim or perpetrator?

The crew’s stories unfold through flashbacks and follow various timelines. What takes shape is a picture of violent disintegration in which the prey are easy targets, impri­soned alongside some sort of lethal force. It’s a whodunit, or a whatdunit, in a closed environment, where everyone is a suspect and everyone, it seems, has something to hide.

This cursed polar outpost is where we find Japanese microbiologist Aki Kobayashi (Tomohisa Yamashita) in HBO Asia’s six-part mystery-thriller The Head, in conjunction with Hulu Japan.

For 35-year-old Yamashita, playing a character he describes as “talented, smart, considerate, sharp-tongued”, meant a new way of working.

As one of Japan’s foremost pop gods – both as a vocalist with News and a solo artist – and already having enjoyed a lengthy career in movies and television, Yamashita was accustomed to the rigours of performing on stage and screen in Japan.

But here, in the remotest of locations, he found himself part of a United Nations of talent with O’Donnelly (Mary Queen of Scots, 2018), John Lynch (Sliding Doors, 1998), Alexandre Willaume (Tomb Raider, 2018), Sandra Andreis (The Girl with the Dragon Tattoo, 2011), Álvaro Morte (Money Heist, 2017), Amelia Hoy (Killing Eve, 2019), Chris Reilly (Everest, 2015), Richard Sammel (Inglourious Basterds, 2009), Tom Lawrence (The King, 2019) … the list goes on.

“I was a bit nervous at first,” admits Yamashita, “but I soon realised we all shared the same passion for making the best show […] and being the only Asian in the cast was not important at all.

“[People like] Álvaro and Katharine are really great. Álvaro is very frank and friendly and he taught me some Spanish – like ‘aqui’, for ‘here’, which sounds the same as ‘Aki’.

“Before filming started, director Jorge Dorado arranged a ‘date’ for Katharine and me. We spent a day together, just by ourselves, like lovers. That helped me feel intimate towards her, as Aki does towards Maggie, from the begin­ning of shooting. But there’s a mysterious side to him, too, and he’s not your typical egghead. Most importantly, the story is so unpredictable it’s beyond imagination.”

Yamashita earned his polar stripes not in the Antarctic but in subtropical Tenerife, in the Canary Islands, where Spain’s Mediapro Studio had constructed a 2,000-square-metre ice-station replica.

“The set was too huge and complex to remember it all at first,” Yamashita recalls of the location where most of the action takes place, often with the actors in full protect­ive winter gear, which posed its own problems.

“We shot the winter scenes in summer, with very limited air conditioning,” he says. “We had to wear thick, cold-proof winter garments and act like we were nearly frozen – while we were sweating heavily beneath the costumes.”

In a recent – virtual – global media conference, which the cast signed into from their homes, Lynch described how, on the purpose-built set, “all was in place to allow the actors to go for it”, but that climactic complications, not least “34-degree heat” meant they “had the sense that we couldn’t get away from the subject we were tackling. We tried to stay in the ‘station’, which was oppressive, but informative. A lot of research had been done on conditions in the Antarctic”.

Lynch was also alluding to the idea that the polar region became, in effect, its own character, which as the story develops influences “the human factor, because everybody is linked. This is not the first time they have all been sta­tioned together. What happened in the past that haunted everyone? When the past is an enemy, the present becomes a battlefield”, he said cryptically.

As superstar scientist Arthur Wilde, Lynch commands much authority around Polaris VI – and is also Aki’s boss.

“Aki is a talented scientist and it’s his first time on the ice,” says Yamashita. “He has also made a huge effort to grab this opportunity to work for Arthur in Antarctica. For myself, I was lucky to have played a biologist in my previous work in Japan. That helped me to some extent,” but “Aki seems to have a deep trauma about something. I don’t have that, but I feel a lot of sympathy with him as a human being, especially in his eagerness and his passion. Another differ­ence is that he has a much sharper tongue than I do.”

During the course of Aki’s research with his superior, it becomes apparent that Arthur’s celebrity is based on his having invented a means of converting carbon dioxide into something far less damaging for the planet, with profound implications for global warming.

What the egotistical Arthur is reluctant to broadcast, however, is that he should be sharing the credit with colleague Dr Annika Lundqvist (Laura Bach), who is married to the station’s summer commander, Johan Berg (Willaume).

There is an undercurrent of tension and peril in the stale base air almost from the onset of night; and when Johan and his team show up again, one of the two “winterers” missing is Annika – another potential victim and potential killer. With the police still days away and Johan desperate to find his wife alive, he begins his own investigation.

“It’s a thriller with no police,” executive producer Ran Tellem says. “The ticking time bomb of the story is Annika’s whereabouts. And every time you think you know the characters there’s something else. The moment you think you know the story it slips from your grasp.”

“It’s a big story confined to a small area and told from different characters’ points of view,” says Willaume. “In every corner Johan turns to there’s a new truth or lie and revelations about what might have happened. He has to connect the dots and at the same time he is searching for his wife, so there are tears, panic and the realisation that there’s good and bad in humanity.”

As Johan warns a researcher early in proceedings: “The ice calls the strangest kind of people – people on the run, people with something to hide.”

For Bach, there is a sense of the rage often felt by women in a world controlled by men. “Annika is in a male-dominated field,” she says, adding that the discovery Annika made with Arthur could “save millions of people. But everyone at the base has something to cover up and all those layers show the depth of the story. It’s not just plot-driven; the interesting idea is the extent to which people will go for justice – and to conceal things”.

And themes of isolation, loneliness and despair have more resonance than ever for viewers across the world who feel stranded and perhaps forgotten as Covid-19 makes its deadly rounds. “Something that couldn’t have been predicted,” as Tellem puts it, has given The Head additional relevance – and in Yamashita’s case, focused his energies on being productive.

“I make it a daily routine to train my muscles for an hour in the morning. I’ve been doing this for many years, but these days it’s in my room because I can’t go to the gym,” he says. “I’ve also made it a rule to do something creative every day, such as shooting or editing videos, writing lyrics, painting or cooking. I try to stimulate my brain each day.”

And when the pandemic has abated? “Back to live concerts, of course! I want to shout to my heart’s content and have huge fun together with my fans,” he says. Not that those fans, who know Yamashita by his nickname, Yamapi, will have to wait too long to hear new material. Some outdoor scenes in The Head were shot in the frozen expanses of Iceland, which inspired him to write and sing the show’s theme tune, Nights Cold.

Before long, with a complex psycho-thriller soon to be under his belt, Yamashita is likely to find himself a hot pro­perty. How will he choose future film and television projects?

“I don’t have a certain genre or type of role in mind, but I always try to be prepared to take any opportunity that arises,” he says. “Whether that will now be domestic or international is not important.

“I once received a letter from a boy who had seen me playing a doctor. He wrote that he had decided to become a doctor like me in the show to save people in need. That letter encouraged me to choose roles in the hope of conveying something good to viewers.

“When I was younger, I really didn’t care about others,” he admits. “Now I realise I’ve come to be interested in other people. I don’t have any specific ambitions to become a producer, director or screenwriter, but I am interested in learning about the many things I haven’t experienced. I believe forthcoming chances and encounters will lead me to the right path.”

The Head is airing on HBO on Fridays at 9pm and streaming on HBO Go.