Mr KJ Apa is hot. To be fair, it’s 19°C, which feels lovely under the shade of million-dollar Mediterranean landscaping in Laurel Canyon, Los Angeles, but sweltering in the sun. Mr Apa is cheerfully roasting himself on the deck of a house borrowed for our photo shoot. The house is all sharp brutalist lines and stern concrete. It looms in striking contrast to Mr Apa, who exudes an Abercrombie joie de vivre.

He moves around the table like a sundial as we speak, following patches of shade. He undoes a few buttons of his shirt, a beachy brown seersuckerish button-up, to better take the breeze. Then he grabs a cigarette from a pack of American Spirits that materialised on the table before he sat down.

“I’m trying to get a tan,” he says, squinting joyfully into the sun like a golden retriever with its head out the car window. I worry for his delicate ginger complexion and then remember that his flaming red hair is fake. This evening he’ll fly back to Vancouver, British Columbia, where he’s shooting the fourth season of The CW’s teen drama Riverdale. Mr Apa’s off-season hair is a dark brown, almost black, like his eyebrows. His brows were dyed to match his hair for the first season of the show, but the process was burning his skin, so he put an end to it. The hair was non-negotiable. It is the trademark of his character, Archie, from the comics on which the show is based.

“I’m half Samoan, but nobody knows it because I’m white and I have red hair,” he says. The “K” in KJ is Keneti, a Samoan name (“J” is James). “My dad is a chief in Samoa. I almost identify more as a Samoan than I do as a New Zealander, just because I grew up with so much Samoan family and the Samoan culture is really close to me. I feel ashamed of myself for not pursuing it more, for not spending more time with my Samoan side because I’m out there all the time.”

Mr Apa, who is now 22, grew up in New Zealand and kicked off his acting career in high school on a soap opera called Shortland Street. It was a baptism of fire. The show shot 25 scenes a day, so Mr Apa got used to learning lines quickly. After two years on Shortland Street, he took a role in a teen drama called The Cul de Sac and then, because opportunities in New Zealand are limited for actors, Mr Apa turned his sights northeast. In short order, he was cast as a teenage Mr Dennis Quaid in A Dog’s Purpose and, a year later, he scored the starring role in Riverdale.

Riverdale has made it more difficult for red-haired Mr Apa to move through the world unaccosted, but he says most people don’t recognise him when he has brown hair. For the uninitiated, Riverdale is a loose, dark adaptation of the Archie comics, which, since the 1940s, have followed the adventures of Archie Andrews and friends as they navigate the trials of high school and growing up in the fictional town of the same name. Where other teen dramas quickly exhaust the same three plot points – break-ups, deaths and pregnancies – Riverdale the show leans into the unexpected and, frequently, the inexplicable.

“What’s the most Riverdale thing that has happened on Riverdale? Well, um, I got attacked by a bear,” says Mr Apa. Besides bears, the youths of Riverdale have also battled a supernatural nemesis, a serial killer, levitating babies, a haunted doll and an organ-harvesting cult led by Mr Chad Michael Murray. “We did have a pregnancy,” Mr Apa points out, referring to a character who was sent away to carry her babies to term among corrupt, murderous nuns.

Audiences enjoy Riverdale in part because it is maximalist entertainment set in a beautiful landscape populated by beautiful people. But the cast’s rapport is also magnetic. Particularly with high-school dramas, the chemistry between cast-mates can sometimes feel manufactured. The Riverdale cast, on the other hand, seem to be having a fantastic time onscreen and off. I ask Mr Apa about a paparazzi shot of him and Mr Cole Sprouse, who plays Archie’s friend Jughead. Mr Sprouse is crouched down, Instagram boyfriend-style, and Mr Apa is leaning against some rocks, posing and looking into the distance. They were on holiday in New Zealand, Mr Apa starts to explain. Then he laughs. “Whenever you’re with Cole and he’s got a camera, at some point you’re bound to be asked to stand somewhere, to pose a certain way.”

From its first season, Riverdale was a perfect incubator for a young actor. Besides the other actors Mr Apa’s age, the show has drawn some legends. American treasures Mr Luke Perry and Ms Molly Ringwald have played Archie’s parents. From them he learned to ford the river of surprises that stardom brings. “I think privacy is everything,” he says after politely but firmly deflecting a question about his newly Instagram-official girlfriend. “I really do work hard on protecting my privacy, my home, my family, the people I love. Luke taught me that.” Riverdale surrounded Mr Apa with friends and mentors, and it was fun.

Mr Perry died suddenly of a stroke in March 2019. “It changed everything when Luke passed,” says Mr Apa. “I had never gone through anything like that before. I’ve never lost anyone close to me, so it was a really hard time. It’s still hard.” He’s approached every question so far with a grin, but now he deflates. “Going to work, I can just feel that he’s not there any more. We had a really, really, really good relationship, me and Luke. He was just kind of a guy that kept us, especially me, grounded because he’d been through all of this stuff. I was so blessed to have him in my life to say, ‘Maybe don’t do that,’ or, ‘This is a good idea.’ Just giving me advice. I miss him. I just miss talking to him. I miss listening to him.”

Mr Apa knew Mr Perry’s health had declined, but the news that he was gone walloped him. He can’t remember the moment he found out. He thinks a showrunner called him. The cast took a few days off work, but when they returned, Mr Apa says, it was brutal.

“Last year was probably the hardest year of my life,” he says. It wasn’t just Mr Perry’s death. Mr Apa was young, an extremely long way from home and he felt alone. But, he says, the year’s trials changed him for the better. “It made me really think,” he says. “What kind of man do I want to be? And I’m still figuring it out.”

When Mr Apa received the script for I Still Believe, a biopic of the singer Mr Jeremy Camp, directed by Messrs Andrew and Jon Erwin, he felt intimidated. He was well-suited to roles in teen dramas, where stars often looked like they played rugby in New Zealand, which Mr Apa did, but here was a chance to show off his range. The Erwin brothers deal in fairly heavy-handed Christian dramas. A previous film they directed, I Can Only Imagine, tells the story of the best-selling Christian single of all time. (Mr Apa grew up in a Christian household, but says he doesn’t put a label on his faith.) “I read the script and I loved it – I cried,” he says. “But I didn’t want to do it.”

He was terrified of playing Mr Camp, he says, because as well as Mr Camp being a real person, who is still alive to judge the performance – “which is another whole bag” – the film orbits around the death of his wife. Some of the scenes were extremely emotional and Mr Apa was concerned he wasn’t capable enough as an actor. Mr Andrew Erwin later told him this was one reason why they were so interested in casting him. They knew he would approach it as a personal test. “I was scared shitless,” says Mr Apa. “I’m just proud of myself for doing it and, watching it back, I feel proud of the work that I did.”

If there’s a through line to his roles, it’s that a disproportionate number of Mr Apa’s characters play the guitar. (Fun fact: Mr Ed Sheeran made a cameo appearance in a 2014 episode of Shortland Street and gave Mr Apa – Kane Jenkins – some music advice.) Has Mr Apa ever considered a career in music?

No, he says, and he probably won’t do another film playing a musician, lest he become the guy whose characters all moodily play the guitar. He did, though, dip a toe in music when he was 14. He made an instrumental guitar album with his father in their home studio. Mr Apa composed the songs on his guitar and they recorded it in a month. “I was pumped about it because I was only 14,” he says. “I was like, yeah, I have an album. I love Joe Satriani and Steve Vai, and I remember thinking I was the man. There was no emotion behind it. It was just me trying to be cool.”

I feel like a nagging parent asking Mr Apa about his plan. The question comes out anyway. What’s the long game? “People ask me that all the time,” he says. “I don’t know. I literally just go with the flow. I want to work on things that inspire me and that challenge me, but at the end of the day, I don’t really have a plan.”

By the time we wrap up, Mr Apa has unbuttoned his shirt to the fourth button. He has one leg stretched out on an unoccupied chair and he’s flung an arm over the back of another. The hardest year of his life is behind him. Tonight, he’ll fly back to Vancouver to work with people he likes on a very fun show. He looks completely carefree – and very cool.

I Still Believe_ is out 13 March (US); 20 March (UK)_