For entrepreneurs hoping to get Masayoshi Son’s backing, the global outbreak of Covid-19 has made it harder than ever to meet the billionaire SoftBank founder in person.

Even after two years of the pandemic, Son has stopped travelling overseas, switching instead to online video chats. Visitors from both in and outside of Japan are required to take PCR tests for three successive days before meeting him.

Management of health risks has become a priority for any chief executive during the pandemic. But deepening succession turmoil has cranked up the risk of a figure as irreplaceable as Son from getting ill.

In the past two years alone, a number of senior executives have left or pulled back from the Japanese group. The latest and perhaps most significant is Rajeev Misra, head of the $100bn Vision Fund who is stepping back from the company’s top responsibilities to launch a fund backed by Abu Dhabi.

Former Sprint chief executive Marcelo Claure left this year, and Katsunori Sago, chief strategy officer and former Goldman Sachs executive, resigned last year. While Son has not publicly acknowledged it, all three individuals were regarded as potential heirs.

“It’s fine if Rajeev was the successor or if it’s somebody else but what’s worrying is the constant coming and going of people. Masayoshi Son’s succession issue is a risk for financial institutions as well,” said a banker who works closely with Son.

There were other high-profile departures — including the chief compliance officer and a former Deutsche Bank trader who ran SoftBank’s shortlived internal hedge fund — and the reasons are different for each. Some were reported to have felt they were underused or were unhappy with their pay, while others were concerned about compliance issues at the group or left after internal clashes within the senior leadership.

The flurry of departures coincides with historic losses at the Vision Fund caused by a rout in technology stocks and a regulatory crackdown in China.

Succession problems are pervasive across corporate Japan and businesses with ageing owners are increasingly being forced to shut down owing to a shortage of heirs. Two friends of Son — the founders of Apple supplier Nidec and Uniqlo owner Fast Retailing — have also struggled to find a successor.

In April, Shigenobu Nagamori, the 77-year-old founder of Nidec and a former SoftBank board member, returned to the role of chief executive and demoted his handpicked heir following a fall in the group’s share price. “I am not going to rush with the successor issue. I am very fit so I don’t want to be treated like an old man,” he told investors.

Son, who will turn 65 next month, has also downplayed the succession issue, saying a shift to an investment group has made it easier for him to run the company without being in charge of day-to-day operations. He plans to lead the company beyond the age of 70.

“I am definitely going to search for a successor but I want to keep having a bit more fun. I’m really in the best condition right now,” Son said in February.

Son is notorious for being attracted to figures with big personalities and falling out with them. His bromance with Nikesh Arora, the former Google executive and another of Son’s anointed heirs, ended abruptly in 2016 after he decided to stay in charge. Arora blamed his departure on that shift in the timing of the leadership change. But the falling out also happened when Son was about to make a radical turn in the company’s strategic direction.

In Arora’s case, his plan to transform SoftBank into an Asian version of Warren Buffett’s Berkshire Hathaway was never compatible with Son’s freewheeling way of doing deals. Shortly after Arora departed, Son announced the $32bn acquisition of British chip designer Arm, which he later tried and failed to offload to California-based chipmaker Nvidia.

Similarly, Sago joined SoftBank in 2018, a year after the launch of the Vision Fund. But he struggled to find a role for himself after the group shifted from an operator of assets to a global technology investor, and it quickly became clear he was not a successor.

Misra may have found something more exciting with his new fund but the timing of his departure is fuelling speculation about the Vision Fund’s future. It also begs the question of whether Son is off doing something new again. If that is the case, it is likely he will not be searching for a successor anytime soon — at least until SoftBank’s strategy is clearer.

kana.inagaki@ft.com