A life between the lines

Among Michael ByungJu Kim’s documented possessions is a collection of signed first editions. Forbes Asia described it in 2020, alongside the publication of his first novel, Offerings. For a man who made his fortune buying businesses, the books offer a more personal introduction: objects valued for the words inside them, and for the trace of the person who wrote them.

The fortune is substantial. Forbes estimated Kim’s personal net worth at $7.7 billion on September 29, 2026, identifying private equity as its source. He cofounded MBK Partners, whose name carries his initials. The estimate puts a scale on a career spent organising capital and investing in businesses.

MBK’s own website describes a business managing $33 billion in capital, focused on Korea, Japan and China. Its investors entrust money to funds that acquire stakes in companies; the manager helps shape those businesses and seeks returns over time. Kim’s position at the firm sits at the centre of his financial success, but its managed capital belongs to an investment structure involving other investors.

The portfolio makes the distinction concrete. MBK identifies Chinese car-rental company CAR with named buyout and special-situations funds, and Korean commerce business Connect Wave with Fund V. It also lists past investments such as Coway, exited in March 2019, and Apex Logistics, exited in May 2021. The named funds and exit dates distinguish investments held through MBK’s funds from deals already completed. Familiar consumer businesses give an otherwise abstract financial career a recognisable everyday reach.

His earlier work took him through Goldman Sachs, Salomon Smith Barney and Carlyle, where he became president of Asia. His official biography places the founding of MBK in 2005, after those years working across international finance. That history matters to the scale of his later success: the independent firm grew from experience at established institutions and from relationships built across markets, rather than appearing fully formed with its founder’s initials on the door.

The same 2020 profile interviewed him from a New York condominium overlooking Central Park. It also described his marriage to Kyung-ah Park, daughter of Posco founder and former prime minister Park Tae-joon. Introduced in New York, the couple married in 1991.

By the time of Julia Hanna’s 2024 Harvard Business School profile, Kim and Park were travelling frequently between Seoul and New York. The cultural institutions on his itinerary included the Metropolitan Museum of Art, the New York Public Library and Carnegie Hall, on whose boards the article placed him. There was a less formal allegiance too: he was a Yankees fan who still hoped to own a professional baseball team.

Writing had occupied him long before his first novel reached readers. Hanna described an early manuscript submitted to an agent while he was at business school, followed by advice to put it away and try again when he had more to say. Kim did. In that account, he saw writing and dealmaking as related acts of connecting ideas. The book was a parallel ambition with its own disappointments, revisions and long wait.

Offerings follows Dae Joon, a Korean-born banker also known as Shane, through the Asian financial crisis. Arcade’s synopsis sets the financial emergency beside the pressures of being an eldest son, a father’s expectations and divided loyalties. The protagonist has pursued Wall Street instead of the scholarly life his father wanted. Family, ambition and belonging give the financial plot its personal stakes.

A complete account must also confront Homeplus, the retailer MBK acquired in 2015. The Korea Times reported in January 2026 that prosecutors alleged short-term debt had been issued despite an anticipated credit downgrade before the retailer entered rehabilitation. A Seoul court rejected detention warrants, finding the evidence then insufficient to justify detention. MBK disputed the prosecution’s interpretation and defended its efforts to restore the business. Rejection of detention was not a verdict deciding the allegations.

The investigation continued. UPI reported on September 12 that prosecutors had again questioned Kim about the debt issuance. Its account noted MBK’s previous denial, including its position that the actions were intended to help Homeplus through financial difficulty. The case belongs in the picture of his career as an unresolved investigation, with the allegation and response both visible.

There has also been a direct personal financial consequence. On September 29, Aju Press reported MBK’s statement that Kim would repay 66.4 billion won in principal and interest on an emergency loan he had guaranteed for Homeplus. According to the firm, 34.2 billion won had been settled and the remainder would be paid from his own funds the following week, without seeking reimbursement from the retailer. The report also said the court approved Homeplus’s rehabilitation plan on September 2. The promised final payment remained prospective at publication.

The signed books, the novel and the institutions carrying his support tell one part of Kim’s story. The businesses, their investors and the people affected when an investment goes wrong tell another. What makes the portrait worth following is the relationship between those parts: how a man who has written about duty and divided loyalties navigates the demands attached to his own wealth and influence.