When a neighborhood teenager showed up on Charlie Munger’s doorstep with a Hebrew Bible, he little thought the encounter would lead to an unlikely friendship—and an investment in California apartment complexes whose values later soared. The investment partnership is profiled in an article in Bloomberg.

Munger, 97, is best known as Warren Buffet’s longtime business partner. When 17-year-old Avi Mayer came to Munger’s door with the Bible—which Munger couldn’t read—they struck up a friendship. Years later, they decided to partner to buy buildings through Mayer’s business, Afton Properties. Though it’s unknown how much Munger’s initial investment was, Afton has bought more apartments in California than anyone else in 2020, the article details.

Demand for apartments is at its highest since the 1970s, pushing rents higher and boosting the value of apartments. Prices for multifamily housing gained 15% in 2021 (through August), and rents in Southern California rose 16% since April of last year (though in downtown L.A. they fell 8.1%).

Afton spent $423 million last year on more than 1700 units, focusing on garden-style apartment buildings. That may seem unglamorous, but by buying with a long-term hold strategy, Afton has amassed a real estate portfolio worth an estimated $1.2 billion. Part of their strategy is to improve the complexes they buy; Munger has said they spent $600,000 on trees the first year of their partnership, noting that there’s more money to be made by taking care of the customer.