LOS ANGELES — Sam Asghari is a nascent actor and erstwhile personal trainer. But this highly polite, handsome and friendly 27-year-old is better known to millions as the fiancé of a 39-year-old woman who was, for years, the biggest pop star in the world, control over whose personal life and $60 million estate was, 13 years ago, stripped from her and reassigned to her father (and a court-appointed lawyer to co-manage finances) in a controversial and secretive arrangement from which she has been forcefully and publicly trying to extricate herself; a woman who has been, for years, photographed in the regular company of no adult save Mr. Asghari, and whom he declined to acknowledge, by name or even oblique reference, as a condition of granting an interview.

That Mr. Asghari’s extremely famous fiancée, Britney Spears, is engaged to marry him is one of few details about her private life that is public knowledge. Both have said in interviews that they met in 2016 when he appeared in a music video for her single “Slumber Party” (featuring Tinashe), in the role of contemplative observer as she crawls down a banquet table to lap up what appears to be spilled milk.

Since then, the pair have shown themselves together many times on their Instagram accounts — typically engaged in a physical fitness activity, relaxing in a cloudless vacation spot, mugging to the camera at close range or some configuration of all three. The couple announced their engagement on Instagram in September (he with a photo; she with a compilation of clips in which she flashed her diamond ring to the camera).

But particulars relating to virtually every other aspect of Mr. Asghari’s fiancée’s life are known only to individuals with access to confidential court records pertaining to the conservatorship that governed her existence since 2008, and was terminated by a judge this week. Her relationship with Mr. Asghari necessarily sprouted within the parameters of this legal contrivance, the terms of which are so thoroughly concealed that, for more than a decade, outsiders could only guess as to how anyone in her circle — let alone how she herself — felt about it.

Then Mr. Asghari spoke out. On Feb. 9, 2021, he posted an Instagram Story — a temporary item that disappears after 24 hours — with text that read, “I have zero respect for someone trying to control our relationship and constantly throwing obstacles in our way.” The ostensible target of his ire was his girlfriend’s father, the custodian of her estate, to whom Mr. Asghari referred by name in the same message, using an obscenity.

Mr. Asghari’s flouting of the presumed omertà that muzzled discussion, or even acknowledgment, of the conservatorship from anyone it directly affected left spectators ravenous to hear more from him.

Mr. Asghari obliged, after a fashion. He posted information on Instagram about a home teeth whitening system, the Submersible Bronzo Blu Abisso 42mm watch from Panerai, Smrtft adjustable dumbbells and a custom-built Jeep Rubicon. He uploaded images of himself modeling and videos of himself working out. He shared clips and trailers for TV shows in which he had been cast in bit parts as sundry devastatingly handsome men. He has also continued to post about his support for his fiancée; on Friday, he shared a photo of himself flexing, wearing a #FreeBritney T-shirt.

But none of his posts satisfied onlookers’ most pressing curiosities: Who is Mr. Asghari? What is his life like? And how did any of this happen?

Mr. Asghari’s Work Endeavors

On a Friday in October, Mr. Asghari arrived at a predetermined location in downtown Los Angeles for a photo shoot and hourlong interview, and was joined by his publicist, Brandon Cohen (reticent; black T-shirt; frequently holding phone to ear), and his creative director, who goes by Maxi (garrulous; pink plaid suit; frequently everywhere).

In advance, Mr. Asghari had agreed to teach his interviewer some of the action stunt work he has been working to master. This would provide a natural foray into a discussion of his career goals (action stardom).

Yet, on the day, this plan fell apart completely, its individual components skidding out of reach in previously undiscovered directions. For instance: Upon learning that the interview contained no video component — there had never been a video component — Maxi and Mr. Cohen professed disbelief and skepticism that Mr. Asghari’s stunt demonstrations could be expressed in any format but one designed for the broadcast of moving visual media.

At the suggestion that the essence of the stunts, as well as specific maneuvers, could be described in writing and then pictured by the reader, Maxi voiced strong doubt, “because I have a vivid imagination,” he said, and “I can’t visualize it” — and his dubiousness meant that the stunt demonstration was never attempted.

Mr. Cohen and Maxi also understood the interview to have different start times; according to one of the timelines, a photographer, who arrived for the shoot exactly on time, was either 45 or 90 minutes late. At one point, Maxi declared that the hourlong interview would take 15 minutes.

In conversation, Mr. Asghari — who moved to California from Iran at age 12 to live with his father, who had emigrated seven years earlier — was pleasant. He was loath to express dissatisfaction of any kind, about anything, or to acknowledge any familiarity whatsoever with that state.

Asked what aspect of everyday life he initially found hardest to adjust to after leaving his mother and sisters in Tehran as an adolescent, to travel to a foreign country whose language he did not speak, to live with a father he had not seen since age 4, Mr. Asghari replied: “To be honest with you, it wasn’t hard for me at all. It was easy for me.”

Asked to identify the worst job he ever had, Mr. Asghari, who said his pre-acting work included a stint at Best Buy and rolling sushi for quinceañeras, said each job was as enjoyable as the last because, “I find happiness in every job.”

Asked to rank his work endeavors in order of priority, Mr. Asghari explained that he prioritizes everything in life equally, even when stepping back from it, as he has done with his career in personal training. Asked which of his three older sisters he is closest to, Mr. Asghari said, “I’m closest to all of them.”

And when asked, flat out, “What is your job?” Mr. Asghari replied without hesitation: “I’m a plumber.”

While he exhibited it sparingly, Mr. Asghari has a genuine knack for deadpan humor. The effect is enhanced by his chiseled facial features, which do not immediately suggest comedy; by his shatterproof earnestness, which leaves one unable to see his jokes coming; and by the fact that everything he says is delivered in the same calm tone.

Though deadpan humor can often be mean — a way to leave a straight man twisting in the wind — Mr. Asghari is not. His flippant responses were quickly and invariably followed by genuine answers.

“My job, at the moment, is acting,” he clarified.

One of Mr. Asghari’s most widely seen — though blink-and-you’ll-miss-it — career performances was as a character credited as “Sexy Santa” in an episode of the 2021 HBO Max series “Hacks.” He appeared in a single scene, opposite Jean Smart.

“Acting is not necessarily just shooting TV shows and film,” Mr. Asghari said. “Stunt choreography, coaching, auditioning — those are part of that. So that’s a full-time job.” (For his own entertainment, Mr. Asghari said he watches “performances, not shows.” Asked to name a performance he’d watched recently, Mr. Asghari said, “Hugh Jackman. I watch clips of him acting. Jason Statham, I watch clips of him acting.”)

Although his social media posts often depict him in hot pursuit of physical fitness, Mr. Asghari described personal training as his “waiter job” — that is, a job an aspiring actor holds until he can support himself with acting.

But while he is reorienting his professional trajectory, Mr. Asghari continues to be affiliated with an online personal training subscription service, Asghari Fitness, which, he said, has about 1,000 subscribers.

For $9 a week, subscribers have access to video clips in which a man, sometimes but not always Mr. Asghari, demonstrates exercises including “Bulgarian Split Squat” and “Dumbbell Good Mornings,” along with a suggested workout schedule.

Subscribers also receive a meal plan containing the recipes of up to three meals and three snacks a day.

The recipes are notable for their bare-bones formulations (a dish labeled “Beef Salad” requires 10 minutes’ cook time, four ingredients and four lines of direction, of which the fourth is “Enjoy”), and for the fact that at least some of the accompanying photos seem to have originated from other sources. (A reverse image search for the uncredited “Beef Salad” photo led to a 17-ingredient recipe for “Vietnamese Grilled Aussie Beef Salad” that, according to TrueAussieBeefandLamb.com, takes 40 minutes to prepare).

His website was built by MacroActive, a company whose headquarters are in New Zealand, which supplies a ready-made online platform to aspiring coaches who can use it to host their own fitness-adjacent subscription services. Afluencr, a MacroActive subsidiary in Wales, provides additional management and design elements.

Mr. Asghari said that Asghari Fitness is “always going to be improving,” that “it’s very exclusive,” and that “it’s not something that I’m pushing, or I’m not hoping to make millions of dollars off of it.”

A one-episode stint on HBO Max also “doesn’t pay your bills,” Mr. Asghari said. “If you’re on three, four different films, yeah, it pays your bills.”

None of which quite explains how Mr. Asghari pays his bills — or what they are.

“My biggest expenses are my career,” he said, citing stunt and acting coaching as specific costs. “That’s what I spend money on.”

Mr. Asghari’s Team

If Mr. Asghari is the heart of the Sam Asghari business, Maxi and Mr. Cohen are the palpitations. Maxi interrupted Mr. Asghari’s interview to compliment how it was going; to grab a bagel he had left behind; to suggest answers to various questions to Mr. Asghari, some of which Mr. Asghari disagreed with; to eat the bagel; to announce 15 minutes into the interview that there were 10 minutes left (there were 45 minutes left); to request that Mr. Asghari change back into a pair of jeans he had asked him to change out of; to express gratitude for all that the interview was revealing to him about Mr. Asghari; to declare, while painting gentle curves of green emollient onto Mr. Asghari’s face, “He doesn’t need makeup”; to advise that the article that would result from the interview be titled “Starring in the Mel Gibson Movie” (Mr. Asghari is currently filming a movie with Mr. Gibson); to stand before Mr. Asghari and, while Mr. Asghari was in the middle of a sentence, dab at his lips with a Baby Phat Pink Rose Gold Glitter Hydrogel under-eye mask; to jump in with quick comments, and then say “delete delete delete.”

Mr. Asghari appeared habituated to sudden disturbances. After each disruption, he retrieved the path of his thoughts as nonchalantly as a storm-blown songbird recovers its migratory route to the tropics.

Mr. Asghari met Maxi eight years ago, “at someone’s random house that he was visiting,” Maxi said. Mr. Asghari was working as a personal trainer at the time.

“And so I met Sam and I said, ‘Oh, you’re the next Superman!’” said Maxi, speaking at the speed of ice cubes being blended into iced coffee. “Got him an agent, got him all that.”

It was Maxi’s suggestion, Mr. Asghari said, for him to “start acting.”

The function of the “director” in Maxi’s “creative director” title, is “just to make myself sound glamorous,” Maxi said. “I’m just his friend, basically.”

“Just a friend,” Mr. Asghari echoed.

“His friend who’s taken control,” Maxi said, laughing.

“But, yeah,” Mr. Asghari said, “and then — — ”

“Because I started this,” Maxi said.

Mr. Cohen, on the other hand, first contacted Mr. Asghari six years ago by Facebook Messenger.

“I had a feeling that if I started to work with him and represented him that I could get him great opportunities and build his career from nothing to where it is today,” he said. “I just had an intuition and gut feeling. And as a rep, sometimes you just look at someone and you see — —”

“See how he said ‘nothing’ to ‘where he is today’?” Maxi stage-murmured to Mr. Asghari. They both laughed. “He’s like ‘I took a speck of dirt. …’”

“No!” Mr. Cohen said, in protest.

Mr. Cohen said that Mr. Asghari hung up on him during their first scheduled call. “So I call back, like I always do,” he said. “I just kept calling and being persistent and being there.”

“We just, ever since then, worked together.”

Mr. Asghari’s Destiny

There is no question that Mr. Asghari has acquired a team with a fervent, urgent desire for him to succeed. But their hands-on approach and sheltering management of their adult client’s life created a veil through which Mr. Asghari remained largely indiscernible.

While Maxi and Mr. Cohen’s exact responsibilities relative to Mr. Asghari and to each other were not obvious, what was apparent was that, working in concert yet ofttimes also at odds, these two stewards of Mr. Asghari’s career together created an anxious alternate reality so powerfully felt by them that it intermittently supplanted actual reality for everyone in the immediate vicinity.

It’s unclear which of the two desired that Mr. Asghari channel New York City in his Los Angeles photo shoot.

It was Maxi who deemed the outfit Mr. Asghari wore to his interview — slim-fitting jeans and a storm gray sleeveless hoodie that tightly framed his tremendous biceps — unsuitable for a photo shoot because “he’s not working for ThighMaster”; who styled the designer garments in which Mr. Asghari was instead photographed (“I would never wear any of this!” Mr. Asghari said cheerfully); who declared, “It’s a winter shoot,” as explanation for Mr. Asghari’s wearing a full-length wool and vegan leather coat on a warm, sunny afternoon; who gave Mr. Asghari an “I Love NY” T-shirt to wear; who said, “We’re going out on the street to make it feel like the L.A. version of New York” and “Giving L.A. New York — that’s supposed to be the vibe.”

Yet it was also Maxi who was heard to object afterward, “Brandon apparently said that I was creatively controlling something.”

“Which I do not, just so you know,” he said.

In the conjurings of his publicist and creative director, Mr. Asghari has, for almost a decade, been on track to be the next Superman. The long-anticipated attention of which he is at last the recipient is wholly attributable to his acting talent, work ethic and humility. That Mr. Asghari came to be betrothed to one of the most famous people in the world is irrelevant. Mr. Asghari’s stardom does not — must not, in any way — rely on his connection to her.

Ten days after the couple announced their engagement, a lawyer for Mr. Asghari’s fiancée cited her plans to execute a prenuptial agreement with Mr. Asghari — a process in which her financial conservator would play a major role — as further reason that her father should be suspended as conservator. Though the court granted the request, additional hearings were scheduled to determine future control over her life and finances.

At the first of those hearings, on Friday, a judge terminated the conservatorship, effective immediately.

Mr. Asghari, of course, has been subject to no legal constraints on how — and with whom — his money and time can be spent.

Aglow in butterscotch October sunlight, Mr. Asghari eagerly proffered his cracked iPhone to Maxi. He was keen to play a video of his latest stunt training.

“I care more about your shoot right now,” Maxi replied without watching, determined that Mr. Asghari should achieve his — Mr. Asghari’s — dreams. “We’ve got to get it done.”

Mr. Asghari lowered his phone, unfazed. As directed, he waded gamely into the ornamental vegetation outside a nearby municipal building and began to pose.

Kirsten Noyes contributed research.