It started socially, as business relationships between millionaires and billionaires tend to do. And, in the case of Bob Iger and Joshua Kushner, who are buying the Los Angeles Lakers, a supermodel played matchmaker.

In early 2018, Willow Bay, Mr. Iger’s wife and the dean of the University of Southern California’s journalism school, became friendly with Karlie Kloss, the fashion model and entrepreneur. They bonded over Estée Lauder: The cosmetics giant was preparing to make Ms. Kloss one of its newest faces, three decades after Ms. Bay had modeled for the brand.

Ms. Kloss soon asked Mr. Iger for a favor: Would he sit down with her boyfriend? She was dating Mr. Kushner, the founder of Thrive Capital, an investment firm, and the brother of Jared Kushner, President Trump’s son-in-law.

“I think she thought he would benefit from some of my wisdom,” Mr. Iger, 75, said with a chuckle in a phone interview on Wednesday.

The two men are 34 years apart in age. In 2005, when Mr. Iger became Disney’s chief executive for the first time, Mr. Kushner was still a Harvard undergraduate. By Mr. Iger’s telling, however, it was a bromance at first sight when they met for lunch at Marea, a high-end Italian restaurant in Manhattan.

“I took to him right away,” Mr. Iger said. “Humble, extremely smart, easy to connect with. I quickly learned that he has a lot of wisdom of his own.”

On Friday, Mr. Kushner called Mark Walter, who bought a majority stake in the Lakers last year at a $10 billion valuation, a record for the National Basketball Association. Mr. Kushner, 41, proposed buying a majority stake in the team with Mr. Iger. Their offer, first reported by ESPN on Wednesday, valued the Lakers at an eye-popping $12.5 billion.

“As lifelong N.B.A. fans, we are deeply honored for the opportunity to become stewards of the Los Angeles Lakers, one of the most iconic sports franchises in the world,” Mr. Kushner and Mr. Iger said in a statement.

The deal marks a striking evolution in the relationship between two generations of moguls. Over time, a mentorship has developed into a flourishing business relationship in which Mr. Iger, one of the best-known executives in corporate America, operates within an investment empire built by the younger and lower-profile Mr. Kushner. The Lakers are their biggest undertaking yet.

A spokeswoman for Mr. Kushner said he was unavailable for an interview. His public comments about Mr. Iger in the past were relatively minimal. Mr. Kushner wrote on social media in April that Mr. Iger “leads with boldness and conviction because he knows what he is building and why.”

Although the Lakers are one of the most storied franchises in professional sports, they are navigating a generational transition. The team has won only one championship in the past 16 years — hard times for an organization accustomed to contending for titles. LeBron James, the face of the Lakers for much of the past decade, departed last month for the Philadelphia 76ers.

Before their sale to Mr. Walter, the billionaire chief executive of Guggenheim Partners, the Lakers were owned for decades by Jerry Buss or his children. Mr. Buss turned the Lakers into a revered global brand. Celebrities like Jack Nicholson and Denzel Washington are die-hard fans. The waiting list for season tickets lasts years.

Mr. Iger’s relationship with the N.B.A. is unusually personal. Adam Silver, the league’s commissioner, has been a close friend for more than three decades. It was Mr. Silver who introduced Mr. Iger to his future wife, Ms. Bay, in the 1990s, when she was hosting the television show “NBA Inside Stuff.”

Mr. Kushner is also a longtime N.B.A. fan. He bought a minority stake in the Memphis Grizzlies in 2019. He subsequently sold it and bought into the Miami Heat. Mr. Kushner and Ms. Kloss, who were married in 2018, have been photographed at Knicks games in New York.

A formal business relationship between Mr. Iger and Mr. Kushner began to form about five years ago, as Mr. Iger prepared to leave Disney for the first time. He had stepped down as chief executive in 2020, ending a celebrated 15-year run, and would relinquish his remaining duties as executive chairman at the end of 2021. Mr. Kushner began recruiting him to join Thrive.

In September 2022, Thrive announced Mr. Iger as a venture partner and said he would mentor entrepreneurs and help identify investments. Mr. Iger brought extraordinary access to Hollywood and corporate America, and vast experience buying and integrating companies, including Marvel, Pixar, 21st Century Fox and Lucasfilm. For his part, Mr. Kushner helped Mr. Iger deepen relationships in Silicon Valley, introducing him, for instance, to Sam Altman, OpenAI’s chief executive.

Mr. Iger was at Thrive for only two months. In November 2022, the Disney board abruptly asked him to return as chief executive, replacing his handpicked successor, Bob Chapek, who was flailing. Mr. Iger agreed to return and stepped down from Thrive.

Still, his relationship with Mr. Kushner kept deepening. In 2023, Mr. Iger joined Henry Kravis, the founder of the private equity firm KKR, and a handful of other rarefied investors in buying a piece of Thrive itself. Last year, Mr. Iger and Ms. Bay attended Mr. Kushner’s 40th birthday party at Katz’s Delicatessen in New York.

When Mr. Iger stepped down as Disney’s chief executive for a second time in March, he again went straight to Thrive.

“I fortunately had the freedom to associate myself with just about anyone,” Mr. Iger said. “But I wanted to be extremely selective. I didn’t want to associate myself with anyone who would run contrary to my own values or put my reputation in jeopardy.” (Mr. Iger remains on the Disney board. The company has said he will leave when his contract expires at the end of the year.)

Mr. Iger rejoined Thrive as Mr. Kushner announced an expansion: Thrive Eternal, a vehicle for long-term investments in iconic brands and cultural assets that can’t be replicated by artificial intelligence. (Think Disney theme parks.) Its first investment was a stake in the San Francisco Giants baseball team. In recent months, Thrive Eternal explored a bid for a prospective N.B.A. expansion team in Las Vegas, pivoting instead to the Lakers.

Along with working on Thrive Eternal, Mr. Iger has spent time in recent months on his $45 million superyacht, the Aquarius, and working on a follow-up to his 2019 memoir. On Sunday, he will travel to Anaheim, Calif., to be honored as a Disney Legend, joining a pantheon of influential company figures; he will also have his name permanently added to a window on Disneyland’s Main Street, the company’s highest accolade.

But his purchase of the Lakers with Mr. Kushner is clear evidence that his post-Disney life won’t look much like retirement. Instead, he has found another outlet for the dealmaking and ambition that defined his tenure at Disney.

Perhaps part of the attraction is that Mr. Iger recognizes something familiar in Mr. Kushner.

“He’s a friend, but I also love the ambition,” Mr. Iger said. “It’s infectious.”